The Special Investigations Unit is investigating the death of a man who died in hospital after being shot during a police traffic stop in Brampton, Ont.

Const. Lilly Fitzpatrick says an on-duty officer stopped a vehicle in the Queen Street East and Kennedy Road North area at approximately 10 p.m. Wednesday. The officer then called for another unit, Fitzpatrick says, "but did not ask for a rush on that unit."

Shortly after that, she said the officer activated the emergency button on his portable radio. Fitzpatrick explained that typically occurs when an officer "needs assistance immediately and either can't or doesn’t have time to access the portable radio."

"(The) emergency button went off, we started to receive calls of reports of shots fired," she said.

It is not known how many bullets were fired, but eyewitnesses said they heard approximately three to five gunshots ring out.

Fitzpatrick said the man, whose name has not been released, was struck by police gunfire.

The SIU is an arm's length provincial agency that investigates police-related incidents involving death, serious injury and allegations of sexual assault.