LONDON, ONT. -- The Special Investigations Unit (SIU) has invoked its mandate after the Sarnia Police Service received an allegation that one of its officers had sexually assaulted a member of the public.

According to Sarnia police they received the allegation on June 4 and immediately notified the SIU.

On Wednesday the SIU invoked their mandate and are actively investigating the accusation.

Little is known about the circumstances of the allegation.

On their website the SIU notes that “In cases involving allegations of sexual assault, the SIU, as a general matter, will not release details to the public which could potentially identify the individual alleging a sexual assault or the official who is the subject of the allegation.”