The death of a man found in Lake Ontario near the downtown ferry terminal is being investigated by Toronto's homicide squad, police said Friday morning.

Toronto police confirmed the death shortly before 7 a.m., after the man slipped into the water near the Westin Harbour Castle, in a park next to the downtown ferry terminal.

The man, 21, had been riding a rented bike along the boardwalk before he ended up in the lake at about 3:45 a.m. Police aren't sure if he was pushed, jumped or fell in.

Firefighters pulled the man from the lake, and then emergency crews rushed the unconscious man to hospital, where he was pronounced dead.

Police said Friday that the death was considered suspicious and homicide detectives were participating in the investigation.

No one had been arrested and no charges had been laid, Const. Tony Vella said.

The victim's friend, who was there at the time of the incident, talked to Toronto police Friday morning. He told police that the victim fell over the edge of the boardwalk and into the lake.

Police continue to canvass the scene at Harbour Square Park, looking for evidence where a Bixi bike stands abandoned and an orange life ring lies on the ground.

Anyone with more information is asked to contact Toronto Police Services or Crime Stoppers.

With files from CTV Toronto's Tamara Cherry