Authorities were called to the 100 block of Central Avenue shortly after 11:00 a.m. after the body was found by a maintenance worker.
That location is between the Delaware River and Route 291 and a few blocks from the Commodore Barry Bridge.
When police arrived they found the body of a black male in his 20s wrapped up in black plastic.
An autopsy on the body will be done on Friday, police said.
There is no word yet on the man's identity or how he died.
Police say they do not have a missing person's report that matches the body.
Anyone with information is asked to contact Detective James Nolan at (610) 447-8429.