A Toronto police officer has been charged with assault in connection with the arrest of a man who was later found to be seriously injured.

Ontario's police watchdog, the Special Investigations Unit (SIU), says the incident took place on May 5 after several people called 911 to report that a man was interfering with traffic at an east-end intersection.

The SIU says police were dispatched to Danforth Road and Warden Avenue and arrested a 48-year-old man.

The man was taken to hospital, where he was "found to have" a serious injury, the SIU says.

The unit says as a result of its investigation, Toronto police Sgt. Douglas Campbell has been charged with assault causing bodily harm.

The sergeant is expected to appear in court on Oct. 25.

The SIU investigates incidents involving police that have resulted in death, serious injury, or reports of sexual assault.