Police say speed was behind a single-vehicle rollover on Highway 401 on Wednesday morning that killed three people.

Two back-seat passengers died after being ejected from the gold-coloured BMW in the westbound collector lanes near Dufferin Street just before 1 a.m., Ontario Provincial Police said.

The 31-year old man and 34-year-old woman were not wearing seat belts, investigators said.

The third victim, a man who was sitting in the front passenger seat, died from his injuries at Sunnybrook Hospital Wednesday morning.

The driver, a 31-year-old Toronto man, suffered a broken neck and is in critical condition in hospital, the Toronto Star reported.

The names of the deceased have not yet been released.

Witnesses said the vehicle was travelling at high speed when it ran over the grass median, through the on-ramp and rolled into a ditch, ejecting the two passengers, the Star reported.

The accident closed the collector lanes until 6 a.m.

"We don't know why they lost control, but we do know that they were travelling at a high rate of speed," OPP Const. Dave Woodford told the newspaper.

"Speed was definitely a factor."

Parts of the car had been strewn over a 50-metre area.

"It was like there was almost nothing left of the vehicle," Woodford said. "You wouldn't have been able to tell it was a BMW."

The incident is the latest in a series of high-speed crashes and comes at a time when street racing is under heavy scrutiny by the OPP and the provincial government.

Law enforcement officials have called for harsher punishments and OPP Commissioner Julian Fantino wants to use airplanes to help nab street racers.

He also suggested anyone who is caught driving more than 50 km/h over the speed limit should be treated as a street racer and have their vehicle seized.