A badly decomposed body was discovered behind a pizza shop on Butler’s West End on Tuesday night, and authorities suspect the cause of death was a heroin overdose.

City police said they found a syringe in the back pocket of Bradley J. Newcamp, 29, of Butler. His body was found in grass behind Vocelli Pizza in the 500 block of West Cunningham Street.

An autopsy was unable to determine why Newcamp died but foul play is not suspected.

Butler County Deputy Coroner Larry Barr acknowledged that a cause of death may never be known definitively. He noted that because of the condition of the remains, toxicology tests were ruled out.

Butler police Capt. David Dalcamo said Newcamp may have been dead for “two to four days” before employees of the pizza shop discovered the body and contacted authorities at about 7:40 p.m.

Barr pronounced him dead at about 8:10 p.m.

Investigators identified Newcamp after finding his wallet in his pants pocket. He lived on the West End not far from the pizza shop, authorities said.

Dalcamo said employees told investigators they first noticed a “slight odor” coming from the back door on Sunday. They did not check in back of the store.

The smell persisted on Monday and Tuesday, when workers inspected the area and found the body.

The manager of the pizza shop declined to comment and referred questions to the company’s headquarters in Pittsburgh.

Barr said it appeared the man had been dead, “a while” possibly since Friday or Saturday night.

“It’s not a pretty picture,” Barr said after examining the remains.

Police said they had not received any missing person reports about Newcamp before the discovery of his body. Authorities did not know if the man lived with anyone. His parents live in Mars.

Butler police were aware of Newcamp’s drug problem. Officers arrested him July 11 after he was found passed out against a wall with a syringe on his lap in the 300 block of North Washington Street. A search turned up an empty stamp bag of suspected heroin in his cargo shorts, according to court documents.

Police said they also found two bags of suspected heroin in his wallet.

Newcamp was charged with possession of a controlled substance and drug paraphernalia.