Two officers with the Lethbridge Regional Police Service were called to a west-side home about a disturbance with a weapon shortly after 11 p.m. Sunday.
A police news release says the officers fired their weapons and hit a 26-year-old man, who died from his wounds.
Clif Purvis with the Alberta Serious Incident Response Team (ASIRT) confirms both officers fired "numerous" times, but he's not sure they both hit the man.
He says there were several witnesses in the house. ASIRT investigators from Calgary arrived at the scene early Monday.
The officers were not injured.
A knife was recovered from the scene, but Purvis says he doesn't know if the man threatened the officers with the weapon before he was shot.
"That's something the investigation will try and determine. At this point, I can't say definitively one way or the other," he said.
"We are on scene conducting an independent objective investigation into this incident."
ASIRT is an independent group that investigates cases in which someone is seriously injured or killed as the result of police action. It decides whether criminal charges should be laid against the officers involved.