Defendant was convicted by a jury of one count of criminal sexual conduct in the first degree, MCL 750.520b(l)(a); MSA 28.788(2)(l)(a), and two counts of criminal sexual conduct in the second degree, MCL 750.520c(l)(a); MSA 28.788(3)(l)(a). He was subsequently sentenced to concurrent terms in prison of from fifteen to thirty years on the esc i conviction and from six to fifteen years on each of the two esc n convictions, with credit for 210 days already served. Defendant appeals from all three convictions as of right. We affirm his convictions for esc ii but reverse his conviction for esc i.
Defendant’s convictions arise out of an incident involving his eight-year-old niece. In December of 1983, defendant was asked to babysit for the complainant and her seven-year-old sister while their parents were absent from the home for approximately an hour and a half. During that time, defendant committed the acts of penetration and contact for which he now stands convicted.
As required under the rape-shield statute, MCL 750.520j; MSA 28.788(10), defendant moved prior to trial for the admission of evidence of certain instances of sexual conduct between complainant and her father. In support of his motion, defendant argued that the evidence was relevant to *403explain the complainant’s knowledge of sexual matters and to dispel any inferences of sexual innocence which the jurors might otherwise be inclined to make based on complainant’s youth. Defendant pointed out that if the jurors were not apprised of these other instances of sexual abuse, they might convict on the theory that complainant could not know how to describe the acts that allegedly occurred unless they had in fact occurred.
The trial court denied defendant’s motion on the ground that evidence of complainant’s sexual relationship with a third person was inadmissible under the rape-shield statute and that complainant’s knowledge of sexual matters could in this case be proven by alternative methods so that defendant’s constitutional rights would not be denied. Complainant had been exposed to pornographic movies explicitly depicting those sexual acts which formed the basis of this criminal prosecution. The trial court allowed testimony to this effect and allowed defense counsel to show the jury segments of two of the films. We conclude that the trial court properly denied defendant’s pretrial motion in a manner that preserved his ability to competently present a defense.
This precise issue was addressed in People v Arenda, 416 Mich 1, 13; 330 NW2d 814 (1982), reh den 417 Mich 1105 (1983), where the defendant was convicted of three counts of first-degree criminal sexual conduct involving his eight-year-old son. In that case, the defendant sought to introduce evidence of sexual conduct between the son and other persons to explain the son’s detailed and accurate knowledge of sexual matters. The Supreme Court held that the trial court properly excluded the evidence under the rape-shield statute without denying the defendant his constitu*404tional rights of confrontation and cross-examination, noting:
[I]n most of the cases in which the source of the victim’s ability to describe a sexual act may be relevant, there are other means by which one can inquire into that source of knowledge without necessarily producing evidence of sexual conduct with others. Counsel could inquire whether the victim had any experiences (e.g., reading a book, seeing a movie, conversing with others, schoolwork or witnessing others engaged in such activity) which aided him or her in describing the conduct that is alleged.
The trial court’s ruling on defendant’s pretrial motion in this case is entirely consistent with the Supreme Court’s ruling in Arenda.
In this case, however, we are presented with an issue not presented in Arenda. The prosecution in this case introduced into evidence the medical testimony of Dr. Per Lamont Oakey who had examined complainant in March of 1984 in preparation for adoption proceedings. In response to a query regarding his observations during that examination, Dr. Oakey testified:
A. I noticed that there were some scar-like lesions above the pubic area on this patient that we’re talking about. I also noticed that there was no hymenal ring when I examined her.
Q. Regarding these scars which were found near the pubic area, is it possible that those could have been caused by a burn by a cigarette lighter?
A. Yes.
Q. Is it possible that those scars could have been as much as two to three months old?
A. Yes.
Q. You state you found no hymenal ring?
A. Hymenal.
*405Q. Is that consistent with there having been some intrusion in the vagina of an eight-year old girl?
A. Yes.
Q. Such as — what type of intrusion, if you could give me a general idea would it take to obliterate the hymenal ring?
A. Some type of blunt trauma, some type of penetration with a finger or object. Nothing probably sharp because it would be too painful I would think.
Q. Would an adult male penis, would that be able to obliterate the hymenal ring?
A. It’s possible.
Defense counsel objected and waited until he was outside the presence of the jury to argue that defendant should be allowed to rebut Dr. Oakey’s testimony by presenting evidence regarding other possible sources of scarring and penetration. The trial court denied defendant’s request on the basis of its earlier ruling.
We are persuaded that once the prosecution introduced medical evidence to establish penetration, evidence of alternative sources of penetration became highly relevant to material issues in dispute. At that point, the admission of evidence which merely explained complainant’s detailed and accurate sexual knowledge was no longer sufficient to protect defendant’s constitutional rights of confrontation and cross-examination since penetration, rather than knowledge, was the relevant issue. Clearly, one of the prosecution’s two purposes in introducing Dr. Oakey’s testimony was to establish that penetration had occurred. Defense counsel did cross-examine Dr. Oakey as to other "non-sexual, ordinary” ways in which a hymenal ring could be broken in an eight-year-old girl, but if the jurors viewed Dr. Oakey’s testimony *406as evidence of sexual penetration, their only recourse was to conclude that defendant was the source of that penetration.
In this case, unlike Arenda, allegations of other occurrences of sexual abuse are not merely speculative. Complainant and her sister had been removed from the parental home on the basis of physical and sexual abuse. An investigation by the Department of Social Services resulted in the filing of a petition for termination of parental rights and a hearing on that petition was scheduled one week after the trial conducted in this case. According to the parties’ briefs on appeal, the probate court did enter an order terminating parental rights.
In reviewing the issue presented, we have the benefit of a Supreme Court opinion decided and released after trial had been conducted in this case and therefore not available to the trial court. In People v Hackett, 421 Mich 338; 365 NW2d 120 (1984), the Supreme Court further interpreted the rape-shield statute as generally excluding "evidence of a rape victim’s prior sexual conduct with others, and sexual reputation, when offered to prove that the conduct at issue was consensual or for general impeachment.” 421 Mich 347-348. The Court recognized, however, that such evidence might "in certain limited situations” be "required to preserve a defendant’s constitutional right to confrontation.” 421 Mich 348. Here, defendant did not seek to introduce evidence of sexual assaults upon complainant by her father for the purpose of showing consent or for general impeachment purposes but for the express purpose of rebutting the prosecution’s evidence regarding sexual penetration and the inference that defendant was the person responsible. We conclude that defendant should have been allowed to introduce the excluded evidence.
*407In People v Hackett, the Supreme Court set forth specific procedures which should be followed where a defendant seeks to establish the relevancy and admissibility of a rape victim’s sexual conduct with others:
The defendant is obligated initially to make an offer of proof as to the proposed evidence and to demonstrate its relevance to the purpose for which it is sought to be admitted. Unless there is a sufficient showing of relevancy in the defendant’s offer of proof, the trial court will deny the motion. If there is a sufficient offer of proof as to a defendant’s constitutional right to confrontation, as distinct simply from use of sexual conduct as evidence of character or for impeachment, the trial court shall order an in camera evidentiary hearing to determine the admissibility of such evidence in light of the constitutional inquiry previously stated. At this hearing, the trial court has, as always, the responsibility to restrict the scope of cross-examination to prevent questions which would harass, annoy or humiliate sexual assault victims and to guard against mere fishing expeditions. . . . Moreover, the trial court continues to possess the discretionary power to exclude relevant evidence offered for any purpose where its probative value is substantially outweighed by the risks of unfair prejudice, confusion of issues, or misleading the jury. [Citation omitted. 421 Mich 350-351.]
If defendant, on remand, is retried on the esc i count an in camera hearing shall be conducted after which the trial court shall place appropriate limitations upon the method by which defendant may present the evidence to the jury.
Affirmed in part, reversed in part, and remanded.
R. L. Tahvonen, J., concurred.