SIU probing OPP case that triggered major police response, road closure in north London

The province's police watchdog has invoked its mandate after a male suspect was hospitalized Saturday night after he became unresponsive during an incident in London's north end.

A small army of police vehicles descended upon a stretch of Richmond Street near Jacksway Crescent shortly after 9:30 p.m., just outside of CF Masonville Place.

The investigation led to Richmond Street being closed south of Fanshawe Park Road overnight and into Sunday afternoon for reasons that remain murky.

In a statement Sunday afternoon, provincial police said they had been called to an address on Butler Street in Lucan around 9 p.m. for reports of a disturbance.

Police said a man fled the scene when officers arrived, striking two cruisers and driving toward London.

OPP said they located and stopped the vehicle in London with the help of city police, and "during the interaction with police, the male became unresponsive."

"Officers administered first aid, and the male was transported to a local hospital."

The man's condition was not provided, and OPP directed all further inquiries to the Special Investigations Unit (SIU) which had invoked its mandate.

The SIU did not respond to a request for comment from CBC News on Sunday.

The independent government agency investigates police conduct that may have resulted in death, serious injury, sexual assault or the discharge of a firearm at a person.

At the scene on Sunday, investigative attention was focused in part around a black Ford sedan seen on the grassy boulevard on the eastern side of Richmond Street.