Ontario's police watchdog says a former Toronto officer has been charged in relation to alleged sex offences dating back more than four decades.

The Special Investigations Unit says it was "notified of a complaint of a sexual nature" against a former officer, which allegedly occurred between Jan. 1, 1970 and Dec. 31, 1971.

After an investigation, the SIU said it has reasonable grounds to believe that the officer, who served with what was then known as the Metropolitan Toronto Police Force, "committed a criminal offence in relation to two men in Toronto."

Peter John Ross, who is also known as "Peter Piper," faces one count of buggery, two counts of indecent assault, one count of assault with intent to commit buggery and two counts of gross indecency. The language of the charges reflects that of the Criminal Code at the time of the alleged offences. 

The 70-year-old accused is due to appear in a Toronto court on Aug. 26.

A Toronto police spokesman, Const. Victor Kwong, told CBC News that Ross was on the force for less than four years.

The SIU investigates all incidents involving police in which death or serious injury occur, or when allegations of sexual assault are raised.