RICHMOND HILL, Ont. -- Ontario's police watchdog is investigating after a man was found dead north of Toronto just hours following his release from custody.

The Special Investigations Unit says police in York Region made the arrest around 5 p.m. Thursday after allegedly finding an intoxicated man in a car in Richmond Hill .

The 47-year-old suspect was held in a cell for several hours then released to a family member just before 3 a.m.

He was found dead in his home roughly three hours later.

The SIU says three investigators and three forensics specialists are looking into his death.

The agency investigates reports involving police where there has been death, serious injury or allegations of sexual assault.