The man's body was found in Tinicum Township on Thursday April 18th.
The 5'11", 280-pound man was wearing a yellow shirt with distinctive markings.
Investigators released close-up pictures of the shirt Tuesday, hoping someone might recognize the markings and help identify the man.
In addition to the shirt, police say, the man was wearing a tan, long-sleeve thermal undershirt, boxers and booty-style socks similar to the type issued to patients in the hospital.
Anyone who recognizes the clothing in the pictures is asked to contact Tinicum Township Police at 610-521-3830, or Detective Robert Fuss of the Delaware County Criminal Investigations Division at 610-891-4707.