OWEN SOUND, Ont. -- The Special Investigations Unit has cleared a provincial police officer in the shooting death of a 52-year-old man in a standoff south of Owen Sound.

The agency says the man proved himself "a lethal threat" to officers at the scene when he discharged multiple shotgun rounds over a prolonged period and refused to surrender.

The SIU says police were called to a home in Chatsworth Township on April 26 over reports that a man was making threats.

Officers surrounded the property after the man was spotted with a handgun -- but the man fled and later barricaded himself in a garage and fired numerous shots at an OPP vehicle.

After a standoff that lasted into the next day, the man came out of the garage with a shotgun raised toward officers and refused orders to drop the weapon.

One of the officers discharged two rifle rounds and the man ran back into the garage and collapsed. The man -- later identified as Louis Charles Soles of Mooresburg -- died of a single gunshot wound to the chest.

The SIU's forensic investigation later found he had discharged up to 80 shotgun rounds during the standoff.

Given the man's prior conduct, the subject officer was justified in his use of lethal force, SIU Director Ian Scott said in his report.

Scott concluded there are no reasonable grounds to charge the officer.