Ontario's police watchdog says it is investigating after a 53-year-old Chatham man was pronounced deceased after an interaction with police.

The Special Investigations Unit says that, just after 2 a.m. on Sept.8, the Chatham Kent Police Service were called to a convenience store located on Charing Cross Road in Chatham for a report of an “unwanted man.”

Police say the man was arrested on scene, taken to the police station where he was deemed to be in distress and then transported to the hospital. The man was treated for his injuries but died in hospital from his injuries on Sept. 15.

According to the SIU, two investigators and one forensic investigator have been assigned to the case.

Investigators are asking anyone with information to contact them.