The Lambton OPP Marine Unit retrieved a body from the St. Clair River south of Sarnia Thursday morning.
Constable Chris Doupe says the deceased male was discovered by a person on a pleasure craft, in the area of the public boat launch in Mooretown near Courtright Line at around 9:40am.
Doupe says the officers are currently working with the coroner's office and Sarnia police to identify the individual.
He says American police and the U.S. Coast Guard have also been engaged in the investigation.
He says to date, the U.S. authorities say they have no missing persons reports or anyone that has been unaccounted for.
The OPP ask anyone who may have information on this incident to contact them at 519-882-1011 or call Sarnia Lambton Crime Stoppers at 1-800-222-8477.