A 29-year-old man was found dead in a vehicle parked in a residential part of the Plateau-Mont-Royal late Saturday morning.
Const. Danny Richer of the Montreal police said a passerby found the man and called 911 around 11:30 a.m. Saturday.
The man was inside a burgundy-coloured hatchback-type vehicle, parked on Des Érables Avenue between Laurier Avenue and Masson Street.
"[Investigators] did not see any evidence of violence on the body but they did see some suspicious evidence on the scene and around the area. That's why this is considered as a suspicious death," Richer said.
He said investigators were looking into whether the incident happened overnight or early Saturday morning.
Richer said an autopsy would be conducted next week to try to determine the cause of death.
The victim was not known to police.