Photo: Glacier Media

Police say an injured man may have been attacked and left lying in a Vancouver park for hours before help was called.

Const. Tania Visintin says an unknown person called paramedics about the victim and he was rushed to hospital after being found unresponsive in Strathcona Park on Monday.

Visintin says hospital staff alerted police to the suspected assault and the man remains in critical but stable condition.

A statement from police says he may have been on the ground for up to 12 hours before help was called.

Investigators haven't been able to identify the victim and say he's in his late 20s, with dark hair, a bearded chin and may be either Caucasian or Indigenous.

The east Vancouver park where the man was found is also home to a growing tent encampment of several hundred people who say they have nowhere else to live.

Visintin says police want to talk to anyone who may have information about the assault.

"This is a disturbing case considering how seriously the victim was assaulted and the length of time he was lying on the ground injured without any help," she says in the statement.