Calgary police say the death of a man in the Beltline on Sunday may be drug-related.

The man was already dead when police were called to the 700 block of 12th Avenue S.W. around 11:15 p.m. MT for reports of a disturbance in an alley.

They say there was a fight and the man was robbed of a bag.

"It is believed drugs may have played a role," said Staff Sgt. Colin Chisholm.

Witnesses sought

He said the autopsy is scheduled for Wednesday, but they believe the man is in his 30s. 

Chisholm said they hope to find people who saw what happened. While there is surveillance footage from the area, investigators say the incident itself was not caught on video.

"We believe there were people that actually witnessed the confrontation that occurred," he said. 

Police do not yet have an accurate description of the culprit. 

Anyone with information is asked to contact police by calling 403-266-1234 or Calgary Crime Stoppers.