In a news release, the Special Investigations Unit says the incident under investigation occurred on the southeast corner of Gerrard Avenue East and George Street at about 5 p.m.
Three officers were on bicycles and wearing yellow jackets at the time of the interaction with the man, the SIU says.
The SIU says an altercation ensued. The man was arrested and then taken to a local hospital, where he was treated for an arm injury.
Anyone with information is asked to contact the lead SIU investigator at 1-800-787-8529, or at 416-622-0748.
The SIU investigates all incidents involving police in which death or serious injury occur, or when allegations of sexual assault are raised.