TORONTO, ONT. -- A man has died nearly a week after being shot by provincial police in an incident that also left his one-year-old son dead, Ontario's police watchdog announced Thursday.

The Special Investigations Unit said the 33-year-old man died in hospital on Wednesday night, six days after he was shot in Kawartha Lakes, Ont., while police were investigating him for allegedly kidnapping his son.

"When three officers discharged their firearms at the man, the man was struck. He was airlifted to hospital," the SIU said in an update. "Last night at 8:40 p.m., the man succumbed to his injuries."

The agency has said three police officers opened fire on the man after his pickup truck crashed into a cruiser, injuring an officer who was laying down a spike belt.

The man was gravely wounded, the SIU said, and his son was found dead of a gunshot wound in the back seat of the truck.

Coroners performed an autopsy on the boy on Saturday, and the SIU said it has yet to receive a report on its findings.

There's no word on whether the bullet that hit the boy came from one of the officers' firearms or a fourth handgun that was found at the scene.

The agency said it has the three officers' guns, while the Centre of Forensic Sciences has the fourth gun and the man's pickup truck.

The officer who was injured, meanwhile, remains in hospital with serious injuries. The SIU said he's listed in stable condition.

The agency said it has interviewed 10 of 13 officers designated as witnesses to the incident, and it will conduct the remaining interviews in the coming days.

While the SIU is investigating the officers' involvement in the shooting, OPP Commissioner Thomas Carrique said the York Regional Police have been called in to handle other aspects of the probe.

Last Thursday's shooting marked the second time in a week that the SIU was called in to investigate an incident in which a provincial police officer was killed or injured.

Const. Marc Hovingh was shot and killed in the line of duty on Manitoulin Island on Nov. 19 while investigating an "unwanted man" on a property in Gore Bay, Ont.

The man, identified as Gary Brohman, was also fatally shot.

This report by The Canadian Press was first published Dec. 3, 2020.