Ontario’s police watchdog is investigating the death of a 36-year-old man, who died while in custody at the OPP Detachment in Trenton, Ont.

The man was found unresponsive in a cell at the Ontario Provincial Police Detachment Thursday morning, and pronounced dead at the scene.

Ontario Provincial Police said Thursday afternoon that the SIU had invoked its mandate and would be investigating the death of the man.

According to the SIU, Ontario Provincial Police officers arrested the man in the area of Front Street and Dundas Street West at 9:30 a.m. and he was taken to the police station.

“At approximately 10:30 a.m., the man was found to be unresponsive. Emergency Medical Services (EMS) was called, and officers commenced first aid on the man, including the administration of naloxone,” the SIU said.

The man was pronounced dead at the scene.

Three investigators and one forensic investigator have been assigned to the case.

The Special Investigations Unit investigates the conduct of officials that may have resulted in death, serious injury, sexual assault and/or the discharge of a firearm.