The Special Investigations Unit is investigating a fatal shooting involving a 41-year-old man who died by police gunfire following an "interaction" with officers at an Oakville hotel early Friday morning.

Sources told CTV Toronto's John Musselman that the man was a guest at the Monte Carlo Inn, located on South Service Road East. He had checked in early Friday morning. Sources say police were later called to the hotel. They say the man was in distress and was threatening to take his own life.

At approximately 5:30 a.m., Halton Region Paramedic Services were called to the hotel on a report that shots had been fired in or near the lobby.

The SIU has confirmed that three Halton Regional police officers were present at the time of the shooting, and one police firearm was discharged.

"There was an interaction between (police) officers and a 41-year-old man," the SIU said in a statement on Friday. "An officer discharged his firearm and the man was struck."

Guests told CTV Toronto that they heard three loud bangs, then saw heavily armed police officers rush into the hotel

"I thought it was somebody beating on somebody's door," Maurice Blackhorst said.

The man who died was not believed to have had a firearm at the time, an SIU representative said, but he may have had something that could be used as a weapon. Police cannot comment further, as the incident is subject to an SIU investigation.

The man suffered life-threatening injuries, and was rushed to a Hamilton hospital where he later died. His name has not been released.

The SIU investigates all cases involving police where there has been a death, serious injury or allegation of sexual assault.

Anyone who may have information regarding this case is asked to contact the Unit at 416-622-1965 or 1-800-787-8529, ext 1965.

With a report from CTV Toronto's John Musselman