The Special Investigations Unit has been called in to investigate the death of a motorcyclist Saturday night.

The motorcyclist and a marked York Regional Police cruiser collided head on on Queensville Side Road, between Leslie Street and Woodbine Avenue, around 11:15 p.m.

The police watchdog is asking anyone who witnessed the collision to contact the SIU lead investigator at 1-800-787-8529 extension 1935.