Canadian police have ruled out foul play after a man's body was found behind the wall of a women's public toilet in the province of Alberta.

Authorities say the man was alone when he entered the restroom in a Calgary city centre shopping mall last week.

They believe he climbed behind a short wall through the vent shaft, got stuck, and died on the evening of Friday 27 April.

His motivation for crawling behind the wall remains a mystery.

The body of the man, who was in his 20s, was discovered by a maintenance worker on Monday.

The worker removed a wall panel in order to repair a toilet that would not flush and found the remains.

"It is believed that [the victim] climbed on top of a pony [short] wall which was directly behind the toilets and removed a vent cover, which was located on top of the wall," police said in a release.

"The pony wall, used to hide utilities, is approximately 7ft tall and is not connected to the ceiling and has no other access points."

Based on evidence police say they believe the man climbed inside the wall through the vent.

His identity was not released and police say they will not send out any further information because the death is considered accidental.