BANGOR, Maine — The autopsy of a man whose body was found outside an apartment building on Fourth Street early Thursday in what police are calling a suspicious death was completed on Friday, but officials are not releasing his name or saying what killed him.

“They are not going to release anything until Monday,” Bangor police Sgt. Jim Buckley said at 5 p.m. Friday, adding that the detectives covering the case had left for the day.

An eyewitness who spoke to the Bangor Daily News and asked not to be identified said an argument over religion led to the death of the man early Thursday morning. The witness said he was visiting friends in an upstairs apartment at 94-96 Fourth St. when a fight broke out about 5 a.m. Thursday.

“These two were talking about religion. One believed in God. The other one didn’t,” he said Thursday. “They were provoking each other all night and it just escalated into [the person who lived in the apartment] strangling the guy. He couldn’t breathe. I told him to stop but he wouldn’t.”

The witness said he called police.

Bangor police have said dispatch received a hang-up 911 call at 5:09 a.m. Thursday reporting that someone had been injured. When emergency personnel arrived, they found a man dead in the driveway on the 94 side of the duplex, Detective Sgt. Paul Kenison said Thursday outside the apartment.

Detectives Joel Nadeau, Dave Bushey and Larry Ellis and Sgt. Paul Edwards, the department’s blood splatter expert, witnessed the autopsy, which was conducted at the state medical examiner’s office in Augusta on Friday, Kenison said.

A representative from the medical examiner’s office said Friday evening that she could not confirm a news media report that further tests were needed to determine the cause of death. She said the cause of death is “pending.”

Anthony Walton, who lives in a second-story apartment in the back of the eight-unit apartment building, stood on his porch and pointed out the blood trail at the death scene on Friday to two Bangor Daily News reporters.

“The Fire Department tried to clean it up, but it’s still there,” he said.

The stain, which appeared a dark green-yellow in color, started underneath a wooden fire escape on the right side of the building, above which was a broken second-floor window that was missing its screen. The bloodstain jaggedly led from the side of the building to a Dumpster behind the duplex.

No one answered the door at the second-story apartment with the broken window, which is accessed from the front of the building.

Rick Coleman, 22, of Bangor, who spent the night at Walton’s apartment, said he went out on the porch to smoke a cigarette Thursday morning at around 5 a.m. and called the police after seeing the body.

“I’d never seen him before,” he said Thursday of the deceased man. “He was wearing pants and shoes but no shirt.”

The victim also appeared to have a head injury, Coleman said.

The eyewitness to the fight said that once the victim appeared to have stopped breathing, other visitors tried to give him mouth-to-mouth resuscitation.

“I walked outside and called the cops,” he said. “When I came around to the back of the building, the body was being dragged over near the Dumpster. I think someone threw him out the window, but I didn’t see that.”

BDN reporters Judy Harrison and Dawn Gagnon contributed to this article.