Toronto police are requesting the public's help in identifying a suspect in an alleged sexual assault on a TTC bus.

Around 6:15 p.m. on Sunday, a man sexually assaulted a woman while she was boarding a bus at Queen Street West and Ossington Avenue, police said in a Wednesday news release. 

The man followed her onto the bus, which went northbound. The man exited the vehicle at College Street West.

Police have released a surveillance image of the suspect. He is described as approximately 45 years old, about five feet five inches tall, with a thin build, short, thinning brown hair and "bad teeth".

He was last seen wearing a red and white checkered, short-sleeve shirt, blue jeans, black shoes, a wristwatch on his left arm and gold-framed sunglasses with reflective lenses.

Investigators ask anyone with information on the identity of the suspect to contact police at 416-808-1400 or Crime Stoppers at 416-222-8467.