Ontario's Special Investigations Unit has revealed the identity of a woman who died after falling off the back of a motorcycle on Highway 401 near Whitby, east of Toronto, on Friday night.

The SIU, which investigates whenever a civilian is killed or seriously injured in an incident involving police, identified the victim on Wednesday as 40-year old Ioana Bocunescu.

She was the passenger on a motorcycle that was being followed by police on the highway near Lake Ridge Road South.

Durham Regional Police said at the time a 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.

She was then struck by several vehicles was later pronounced dead at the scene, Ontario Provincial Police said in a release on Saturday. The motorcycle did not remain at the scene.

The SIU is still investigating the circumstances surrounding Bocunescu's death.