A police investigation continued in Whitby, east of Toronto, after the death of a motorcycle passenger late Friday night.

Ontario's Special Investigations Unit was involved as police searched for the driver of the motorbike.

Police said a Durham Regional Police cruiser had signalled for the motorcycle to stop just after 11:30 p.m. west of Brock Street. Instead, the motorcycle sped up, causing the passenger to fall off, police said.

The passenger was "struck by one or more westbound motor vehicles" and was later pronounced dead at the scene, Ontario Provincial Police said in a release. The motorcycle did not remain at the scene.

The SIU is called in to investigate whenever police actions are connected with death or serious injury.