What is reasonable and probable grounds for belief in the context of an allegation of sexual assault against an accused?

Reasonable and probable grounds for belief in the context of the allegation of an offence against an accused have been described as an honest belief in the guilt of the accused based upon a full conviction, founded on reasonable grounds, of the existence of a state of circumstances, which, assuming them to be true, would reasonably lead any ordinarily prudent and cautious person, placed in the position of the accuser, to the conclusion that the person charged was probably guilty of the crime imputed. The test contains both a subjective and objective element. There must be both actual belief on the part of the prosecutor and that belief must be reasonable in the circumstances. The existence of reasonable and probable cause is a matter for the judge as opposed to the jury (see Nelles v. Ontario, 1989 CanLII 77 (SCC), [1989] 2 S.C.R. 170).