Ontario's police watchdog is invoking its mandate after a shooting in Toronto's west end that left one man dead and a woman seriously injured.

Police were called to the scene (of Dundas and Bloor) at about 5:30 a.m. Sunday amid reports two people had been shot

Paramedics say a man was shot in the upper torso and a woman was shot in the leg.

The man later died in hospital and the Special Investigations Unit is stepping in to investigate.

The SIU is an arm's length agency that investigates reports involving police where there has been death, serious injury or allegations of sexual assault.