The Bucks County Courier Times reports that determination came after an autopsy Monday. Bucks County Coroner Joseph Campbell says the body had been in the water for at least two weeks.
Campbell says foul play isn't suspected and there were no signs of trauma.
Bristol Township police Lt. Terry Hughes says police are following up on leads and missing person reports to determine the man's identity. He says it will likely depend on dental records.
The body was found by a boater around 3:30 p.m. Saturday behind a Dow Chemical property on the Pennsylvania side of the river in Bristol Township.