They were called about a vehicle in the Maitland River late Friday night around 11.
Police, Huron East Fire, and Huron County Paramedics rushed to an area on Ethel Line south of Brandon Road where a vehicle was discovered in the water.
They say several rescue attempts were made without success.
Member of the West Region OPP Traffic Incident Management & Enforcement Team, OPP Underwater Search and Recovery Unit, and OPP Urban Search and Rescue, Chemical Biological, Radiological Nuclear and Explosive Team were brought in to assist in the investigation.
Crews were able to recover a submerged pick up truck Saturday night around 6 and found a lone deceased occupant inside.
Investigators say they are not releasing the identity of the victim at this time.