Calgary police are investigating a suspicious death in the city’s northwest.

A man was found dead, face down, early Thursday morning outside the Humpty's Restaurant at 46th Street and 16th Avenue N.W. in Montgomery.

Emergency officials say the middle-aged man had died just a short time before.

The cause of death has not been determined but police say it is being treated as suspicious.

The homicide unit is leading the investigation. An autopsy is scheduled for Friday.

“At this point I don’t have any knowledge of any witnesses that have come forward to indicate what has happened to this person,” said Staff Sgt. Jason Bobrowich.

Anyone with information about the incident is asked to call police or Crime Stoppers.