What is the test for cross-examination of a complainant in a sexual assault case?

The principles discussed by Madam Justice McLachlin in the Seaboyer case are summarized by Mr. Justice Cory in Osolin v. The Queen, supra, on pp. 522-523: It might be helpful to summarize the principles that can be taken from Seaboyer with regard to the cross-examination of complainants. Generally, a complainant may be cross-examined for the purpose of eliciting evidence relating to consent and pertaining to credibility when the probative value of that evidence is not substantially outweighed by the danger of unfair prejudice which might flow from it. Cross-examination for the purposes of showing consent or impugning credibility which relies upon rape myths will always be more prejudicial than probative. Such evidence can fulfil no legitimate purpose and would therefore be inadmissible to go to consent or credibility. Cross-examination which has as its aim to elicit such evidence should not be permitted. It will be up to the trial judge to take into consideration all of the evidence presented at the voir dire and to then determine if there is a legitimate purpose for the proposed cross-examination. In each case, the trial judge must carefully balance the fundamentally important right of the accused to a fair trial against the need for reasonable protection of a complainant, particularly where the purpose of the cross-examination may be directed to rape myths . In order to assure the fairness of the trial, where contentious issues arise as to the cross-examination of the complainant, a voir dire should be held. In the voir dire, it will be necessary to show either by way of submissions of counsel, affidavit or viva voce evidence that the proposed cross-examination is appropriate. If at the conclusion of the voir dire the cross-examination is permitted, then the jury must be advised as to the proper use that can be made of the evidence derived from the cross-examination. As a general rule, the trial of an accused on a charge of sexual assault need not and should not become an occasion for putting the complainant s lifestyle and reputation on trial. The exception to this rule will arise in those relatively rare cases where the complainant may be fraudulent, cruelly mischievous or maliciously mendacious.