Opinion of the Court
SULLIVAN, Chief Judge:
On June 21, 1990, appellant was tried by a general court-martial composed of officer and enlisted members at Wuerzburg, Federal Republic of Germany. Contrary to his pleas, he was found guilty of rape and false swearing, in violation of Articles 120 and 134, Uniform Code of Military Justice, 10 USC §§ 920 and 934, respectively. He was sentenced to a dishonorable discharge, confinement for 10 years, total forfeitures, and reduction to Private El. After a post-trial hearing, the convening authority on August 28, 1990, approved the findings, but he set aside the sentence and ordered a [354]*354rehearing thereon. On August 29, 1990, appellant was sentenced by the military judge to a bad-conduct discharge, as well as confinement and forfeiture of $500.00 pay per month for 54 months. The convening authority approved this sentence. On March 27, 1992, the Court of Military Review affirmed the findings of guilty and the sentence. 34 MJ 919.
On August 26, 1992, this Court granted appellant’s petition for grant of review on the following issue:
WHETHER THE MILITARY JUDGE ERRED BY NOT GRANTING A DEFENSE MOTION FOR A REHEARING BASED ON THE DISCOVERY OF NEW EVIDENCE WHICH WOULD HAVE PRODUCED A DIFFERENT RESULT AT TRIAL AND IN DEROGATION OF MILITARY RULE OF EVIDENCE 412 AND THE SIXTH AMENDMENT WHICH INFRINGED UPON APPELLANT’S RIGHT TO PRESENT HIS DEFENSE.
We hold that the military judge clearly abused his discretion when he denied the defense motion for a rehearing on findings based on newly discovered evidence which substantially impeached the prosecutrix’ testimony on a material matter. See United States v. Chadd, 13 USCMA 438, 32 CMR 438 (1963); cf. United States v. Thomas, 11 MJ 135 (CMA 1981). See generally United States v. Scaff 29 MJ 60 (CMA 1989). Furthermore, we hold that the military judge likewise legally erred by relying on Mil.R.Evid. 412, Manual for Courts-Martial, United States, 1984, as a basis for denying this motion for a rehearing. See United States v. Dorsey, 16 MJ 1 (CMA 1983); cf. Olden v. Kentucky, 488 U.S. 227, 109 S.Ct. 480, 102 L.Ed.2d 513 (1988).1
The Court of Military Review summarized the facts concerning the granted issue as follows:
After the initial trial, the trial defense counsel discovered new information about the victim of the rape, SPC W. The military judge held a post-trial Article 39(a), UCMJ, session to determine whether the new evidence required a new trial. United States v. Scaff 29 MJ 60 (CMA 1989). The military judge determined that the new evidence would not have been admissible during the findings portion of the trial and would not have affected the findings of guilty. However, he further determined that the new evidence would affect the sentence portion of the trial. The convening authority set aside the initial sentence and ordered a rehearing on sentence only____
On 29 March 1990, the appellant and SPC W were on duty as assistant charge of quarters (ACQ) for their headquarters unit.
34 MJ 919-20.
The Court of Military Review also found: The newly discovered evidence concerns SPC M, a soldier with whom the victim, SPC W, was having a[n extramarital] sexual relationship.
In the post-trial Article 39(a), UCMJ, session, SPC M testified under a grant of immunity that he and SPC W began a sexual relationship in March 1990 and it continued after the alleged rape by the [355]*355appellant. He engaged in sexual intercourse with SPC W either the day before or the day after the alleged rape by appellant. SPC M testified that SPC W was “just basically someone to have sex with.”
During the first week of May 1990, SPC W attempted suicide by taking an overdose of pills. SPC W testified that her relationship with SPC M had nothing to do with the attempted suicide, even though SPC M had told her three to four days prior to the attempted suicide that they had to limit their relationship. She testified that she also agreed they must limit their relationship. From the discussion of a break-up until the suicide attempt, SPC W and SPC M did not engage in sexual intercourse. However, they did resume sexual activities after the suicide attempt.
At the [pre-trial] Article 32, UCMJ, hearing, SPC W testified that early in the evening of the alleged rape, she was talking to SPC M when the appellant came by to check on her. The trial defense counsel questioned SPC W about her relationship with SPC M. She testified that she did not know why SPC M came to see her on CQ duty and that he was just her associate. She further testified that she only talked to him when she saw him.
34 MJ at 921.-
During the post-trial session under Article 39(a), UCMJ, 10 USC § 839(a), appellant requested a rehearing based on his assertion that newly discovered evidence “would produce a different trial result.” The newly discovered evidence was testimony from SPC W and SPC M that they were engaging in an extramarital relationship before the offense and after it; that SPC M terminated this relationship after the alleged rape; and that both persons affirmatively concealed these facts from the earlier court-martial and other parties. Appellant asserted that this evidence would provide a motive for SPC W to fabricate charges against him, i.e., to protect her extramarital relationship with SPC M. Appellant also contended that SPC W was seeking revenge against him because he was informing others of their sexual intercourse. Finally, he argued that evidence of the extramarital relationship between SPC W and SPC M would produce a different result at trial on sentencing.
However, the military judge denied appellant’s motion for a rehearing, finding that evidence of SPC W’s extramarital relationship with SPC M prior to the rape would not, if considered by a court-martial with the other evidence adduced at trial, produce a substantially more favorable result for appellant. Furthermore, the military judge concluded that admissibility of the evidence of the pre-offense sexual behavior was neither “mandated [n]or otherwise required under either the Fifth or Sixth Amendments to the ... Constitution.” Regarding SPC W’s extramarital relationship with SPC M after the alleged rape, the military judge made similar findings and conclusions, except that the military judge ruled that such evidence was admissible as proper rebuttal to the Government’s aggravation evidence on sentencing (i.e., the trauma of the alleged rape interfered with her marital sex life).
Appellant challenges the post-trial decision of the military judge denying his request for a rehearing based on newly discovered evidence. Art. 39(a) and RCM 1102(b)(2), Manual for Courts-Martial, United States, 1984. See United States v. Scaff, 29 MJ 60 (CMA 1989).2 Such a request should be decided by a military judge in light of the criteria delineated in Article [356]*35673, UCMJ, 10 USC § 873,3 and RCM 1210(f). Id. Legal error (i.e., an abuse of discretion) occurs if the findings of fact upon which he predicates his ruling are not supported by evidence of record; if incorrect legal principles were used by him in deciding this motion; or if his application of the correct legal principles to the facts of a particular case is clearly unreasonable. United States v. Travers, 25 MJ 61, 62-63 (CMA 1987); United States v. Rosser, 6 MJ 267, 271 (CMA 1979). See United States v. Thomas, 3 USCMA 161, 11 CMR 161 (1953).
I
This Court has opined that requests for a new trial, and thus rehearings and reopenings of trial proceedings, are generally disfavored. Relief is granted only if a manifest injustice would result absent a new trial, rehearing, or reopening based on proffered newly discovered evidence. See United States v. Giambra, 33 MJ 331, 335 (CMA 1991); United States v. Bacon, 12 MJ 489, 491-92 (CMA 1982); United States v. Chadd, 13 USCMA at 442, 32 CMR at 442; United States v. Childs, 5 USCMA 270, 273-74, 17 CMR 270, 273-74 (1954).
There are at least three specific showings4 that appellant must make in order to be granted a new trial based on newly discovered evidence: First, “[t]hat the evidence [was] ... discovered since the trial.” Second, “[t]hat the evidence is not such that it would have been discovered by the [appellant] at the time of trial in the exercise of due diligence.” And third, “[t]hat the newly discovered evidence, if considered by a court-martial in the light of all other pertinent evidence, would probably produce a substantially more favorable result for” appellant. Para. 109d, Manual for Courts-Martial, United States, 1969 (Revised edition), which preceded RCM 1210(f)(2), adopted in United States v. Bacon, supra at 491. Application of this three-prong test to post-trial motions for a rehearing or reopening of the trial pursuant to RCM 1102 and Article 39(a) is not inappropriate. See United States v. Scaff, supra at 65-66.
[357]*357Turning to the case sub judice, the military judge made the following findings of fact regarding the first two required showings:
That counsel for the accused exercised due diligence in attempting to ferret out this evidence prior to trial and was unable to raise the quality of this evidence above the level of mere rumor among friends of the accused without any basis in fact. Specifically, the 3-5 persons who had knowledge of the existence of this information, for whatever reason, refused to disclose its existence to the defense prior to the above named accused’s trial.
That only after the conclusion of the above named accused’s trial was counsel for the accused successful in turning what once were mere rumors into testimonial evidence in the form of the testimony of both Specialist \M\ and Specialist [W]. The court is not persuaded by the statements by Specialist [W] that, had anyone asked her before trial as to whether she and Specialist [M] were having an extramarital affair and an ongoing sexual relationship, that she would have willing [sic] volunteered such information to the questioner.
(Emphasis added.)
The Court of Military Review reached a contrary conclusion on the due-diligence question. It asserted that “the military judge did not consider whether the evidence was discoverable prior to trial by the exercise of due diligence.” 34 MJ at 922. However, this was an obvious misreading of the record of trial5 which seriously undermined that court’s holding reversing the military judge.
Moreover, the military judge’s holding itself was clearly supported by the record. Specifically, SPC M testified that he lied to defense counsel when asked whether he and SPC W had a sexual relationship, and SPC W testified that she did not inform defense counsel of an extramarital relationship with SPC M only because she was never specifically asked about one. The military judge was neither required nor did he attach any credibility to SPC W’s additional response that had she been asked about a sexual relationship with SPC M she would have acknowledged it. See United States v. Williams, 21 MJ 360, 362 (CMA 1986). Accordingly, we conclude that the military judge properly found that the first two prongs of the newly-discovered-evidence test were met.
We must now turn to the third requirement for granting a rehearing based on newly discovered evidence. The military judge summarily found that evidence of the victim’s extramarital relationship would probably not produce a substantially more favorable result on findings for appellant. The record before us, however, unquestionably establishes the contrary. It discloses noncumulative, uncontradicted impeachment evidence which was relevant not only to a material issue in this case but the dispositive issue in this case — the victim’s credibility. See United States v. Davis, 960 F.2d 820, 825 (9th Cir.), cert. denied, — U.S. -, 113 S.Ct. 210, 121 L.Ed.2d 150 (1992); United States v. Taglia, 922 F.2d 413, 415 (7th Cir.), cert. denied, — U.S. -, 111 S.Ct. 2040, 114 L.Ed.2d 125 (1991). See generally United States v. Thomas, 11 MJ at 139 n.l (Everett, C.J., concurring in part and dissenting in part) (citing earlier Federal cases). Accordingly, we conclude that the military judge clearly abused his discretion in resolving this prong of the newly-discovered-evidence test against appellant. See generally United States v. Travers, 25 MJ at 62-63.
During the Government’s presentation of evidence on findings at the original trial, testimony was offered by Dr. Bachmeister, a psychiatrist. Dr. Bachmeister testified, over a hearsay objection by defense coun[358]*358sel, to statements made by SPC W regarding the alleged rape. He recounted SPC W’s version of the incident, as well as SPC W’s explanation for attempting suicide within weeks after the alleged rape. According to Dr. Bachmeister, SPC W told him that she tried to kill herself because her chain of command failed to remove her from her place of duty which happened to be in the vicinity of the accused’s place of duty. Dr. Bachmeister then opined that SPC W was suffering from Post Traumatic Stress Disorder which could be caused by a number of events, including rape.
Under cross-examination by defense counsel, Dr. Bachmeister acknowledged that a “wide variety of events” could lead to symptoms of Post Traumatic Stress Disorder. He further testified that his evaluation of SPC W was based, in significant part, on what she told him. However, there is absolutely no indication in the record that SPC W informed Dr. Bachmeister of her extramarital relationship with SPC M and the latter’s efforts to discontinue the relationship. On the contrary, during the post-trial Article 39(a) session, SPC W did state that she had in fact withheld from Dr. Bachmeister all information regarding her relationship with SPC M.
As trial counsel stated to the members during his brief argument on findings, “Members of the panel, it all boils down to this, and this alone, as even the defense told you earlier today, either you believe [SPC W] or you don’t. If you believe her, convict the accused. If you don’t ..., thank you.” Thus, in the absence of physical evidence and direct corroboration testimony, factors affecting credibility of the alleged victim were clearly of critical importance. United States v. Davis and United States v. Taglia, both supra, see 37 MJ at 357. Whereas appellant presented two character witnesses on his behalf, the Government supported its case, and indirectly SPC W’s credibility, with the expert psychiatric testimony of Dr. Bachmeister. His testimony was based, in part, on deceitful and misleading information provided by SPC W. Accordingly, the military judge’s conclusion that the undiscovered extramarital relationship evidence would probably not have produced a substantially more favorable result for appellant is simply unsupported by this record. See United States v. Chadd, supra; cf. United States v. Thomas, 11 MJ 135 (CMA 1981).
The Court of Military Review, reaching the same conclusion as the military judge, recognized that the central point of contention between the parties was the issue of consent. SPC W said that sexual intercourse occurred and that it was without her consent. Appellant testified that sexual intercourse occurred but that it was consensual on both their parts. The Court of Military Review then said:
Secondly, if it had been admitted, the evidence would not have resulted in a different finding by the trier of fact. The appellant asserted at trial that SPC W had a motive to lie about consensual sex with the appellant to protect her relationship with her husband. The trier of fact did not agree with this theory. It is highly unlikely that they would have found that SPC W had a motive to lie to protect a relationship with her lover, SPC M....
34 MJ at 922.
This rationale, while more specific than the military judge’s, was also unsupported by the record. First of all, its premise is incorrect. Defense counsel argued at trial that SPC W lied about consent to protect herself from an abusive husband, not to protect their relationship. Accordingly, the analogy suggested by the Court of Military Review does not logically follow. Second, we note that the newly discovered evidence would also show that SPC W not only had this extramarital relationship with SPC M but that she was dishonest with Dr. Bachmeister about it, concealed it from her husband and a court-martial panel, and advised SPC M not to voluntarily disclose it. The Court of Military Review’s inexplicable disregard of this devastating evidence concerning SPC W’s veracity fatally under[359]*359mines its conclusion that a different verdict would not probably occur.
II
We next address the Government’s remaining contention that the newly discovered evidence would be inadmissible under Mil.R.Evid. 412. This evidentiary rule provides, in pertinent part, as follows:
(a) Notwithstanding any other provision of these rules or this Manual, in a case in which a person is accused of a nonconsensual sexual offense, reputation or opinion evidence of the past sexual behavior of an alleged victim of such non-consensual sexual offense is not admissible.
(b) Notwithstanding any other provision of these rules or this Manual, in a case in which a person is accused of a nonconsensual sexual offense, evidence of a victim’s past sexual behavior other than reputation or opinion evidence is also not admissible, unless such evidence other than reputation or opinion evidence is—
(1) admitted in accordance with [requirements of notice and offer of proof] and is constitutionally required to be admitted; ...
Ten years ago this Court set forth the standard for determining whether the evidence of a victim’s past sexual behavior “is constitutionally required to be admitted.” United States v. Dorsey, supra; see United States v. Elvine, 16 MJ 14 (CMA 1983); United States v. Colon-Angueira, 16 MJ 20 (CMA 1983). The Court unequivocally adopted the Supreme Court’s holding that, where evidence is relevant, material, and favorable to the defense, such evidence “is constitutionally required to be admitted.” See United States v. Valenzuela-Bernal, 458 U.S. 858, 867, 102 S.Ct. 3440, 3446, 73 L.Ed.2d 1193 (1982), cited in United States v. Dorsey, supra at 5 and United States v. Colon-Angueira, 16 MJ at 26; see also United States v. Saipaia, 24 MJ 172, 175 (CMA 1987) (“Primarily, Mil.R.Evid. 412 is a rule of relevance, specifically concerned with the relevance of the victim’s sexual past in a trial for a sex offense.”), cert. denied, 484 U.S. 1004, 108 S.Ct. 694, 98 L.Ed.2d 647 (1988). Furthermore, this constitutionally limited evidentiary rule has been applied by this Court with equal force to evidence of post-offense sexual behavior. See generally United States v. Colon-Angueira, supra.6
In Olden v. Kentucky, 488 U.S. 227, 109 S.Ct. 480, 102 L.Ed.2d 513, the Supreme Court addressed a claim that an accused was denied his Sixth Amendment right to question a prosecuting rape victim about her prior sexual behavior. Confronted with factual circumstances similar to those now before us, the Court held that the accused’s Sixth Amendment right “to be confronted with the witnesses against him” necessarily implies “the right to conduct reasonable cross-examination.” Id. at 231, 109 S.Ct. at 482-483 (citing Davis v. Alaska, 415 U.S. 308, 315-16, 94 S.Ct. 1105, 1109-10, 39 L.Ed.2d 347 (1974)).
Petitioner Olden raised “a defense of consent” to the charge of rape. According to his testimony, the victim “propositioned” him to have sex, and sometime later that evening the petitioner dropped the victim off at her boyfriend’s home. Both the victim and her boyfriend were “married to and living with other people at the time of the incident.” 488 U.S. at 229, 109 S.Ct. at 482. Her boyfriend purportedly observed the petitioner drop off the victim at his home after the petitioner and the victim had consensual sexual intercourse. Olden’s theory of the case was that the victim fabricated the rape story to protect her extramarital relationship with her boyfriend. Notwithstanding this defense theory, the trial judge granted the prosecutor’s motion in limine to exclude all evidence of [360]*360the extramarital affair. Id. at 229-30, 109 S.Ct. at 481-82.
The Supreme Court in Olden reversed the state court of appeal’s affirmance of the conviction. It held that denial of “cross-examination designed to show a prototypical form of bias on the part” of a witness violated the Confrontation Clause of the Sixth Amendment. Id. at 231, 109 S.Ct. at 482. Applying a harmless error analysis of the record, the Court found prejudice. The analysis was based on several factors:
These factors include the importance of the witness’ testimony in the prosecution’s case, whether the testimony was cumulative, the presence or absence of evidence corroborating or contradicting the testimony of the witness on material points, the extent of cross-examination otherwise permitted, and, of course, the overall strength of the prosecution’s case.
Id. at 233, 109 S.Ct. at 483 (quoting Delaware v. Van Arsdall, 475 U.S. 673, 684, 106 S.Ct. 1431, 1438, 89 L.Ed.2d 674 (1986)). It is our view that the Olden and Van Arsdall decisions encompass the test for “constitutionally required” evidence used by this Court in United States v. Dorsey, supra.
In the case now before us, we also conclude that the cross-examination of the victim about her extramarital affair would have been relevant, material, and favorable to the defendant.7 First, as in Olden the evidence was relevant in that it would undermine SPC W’s credibility by providing a reason for her giving false testimony, i.e., that SPC W fabricated the charge to protect her extramarital relationship with SPC M. Cf. Olden v. Kentucky, 488 U.S. at 232, 109 S.Ct. at 483 (witness bias is relevant subject for cross-examination); United States v. Dorsey, supra at 6. Second, the evidence is material and would affect the judgment of the trier of facts, i.e., that SPC W was the Government’s central, indeed crucial, witness.8 Cf. Olden v. Kentucky, 488 U.S. at 233, 109 S.Ct. at 483; United States v. Dorsey, supra at 7; United States v. Colon-Angueira, 16 MJ at 26-27. Finally, SPC M’s testimony is favorable to the defense, i.e., the Government’s evidence was far from overwhelming and such third-party testimony could very well shift the outcome in appellant’s favor. Cf. Olden v. Kentucky, 488 U.S. at 233, 109 S.Ct. at 483; United States v. Colon-Angueira, 16 MJ at 27.
In sum, the record makes clear that this is not a case of far-reaching speculation concerning the probable impact of newly discovered evidence. On the contrary, this case presents a situation in which the sexual-relationship evidence supports direct and reasonable inferences about SPC W’s state of mind at the time of her formal complaint against appellant, i.e., a possible bias on her part. Moreover, as noted above, evidence at the post-trial hearing uncovered startling examples of SPC W’s lack of veracity with respect to this relationship. A newly convened court-martial might rea[361]*361sonably find or infer that SPC W was so concerned about preserving her extramarital relationship with SPC M that she would fabricate a rape charge in response to appellant’s spreading the word of his having had sexual intercourse with her. To the extent that the military judge and the Court of Military Review ignored the possible repercussions of this devastating evidence, we conclude that they clearly abused their discretion. See United States v. Chadd, supra; see also Geders v. United States, 425 U.S. 80, 86-87, 96 S.Ct. 1330, 1334, 47 L.Ed.2d 592 (1976) (trial judge’s limitations on cross-examination reviewed for abuse of discretion).
The decision of the United States Army Court of Military Review is reversed. The findings and sentence are set aside. The record of trial is returned to the Judge Advocate General of the Army. A rehearing may be ordered.
Judge WISS concurs.
SPC W is married to another soldier and is not married to the appellant.