Queensland Police say a man armed with knives advanced towards officers before he was shot dead in Townsville in north Queensland late on Friday.
Police were called to an address on Bel Air Avenue in Kirwan on Friday afternoon to reports of a disturbance, where Steven Angus, 52, was reportedly threatening self-harm.
Acting Chief Superintendent Chris Lawson said it was alleged Mr Angus was holding knives when he approached police.
"As a result, police fired their service firearms," he said.
"First aid was provided and unfortunately, a short time later, after the arrival of QAS (Queensland Ambulance Service), he was pronounced deceased."
The Department of Veterans' Affairs confirmed Mr Angus was a former serviceman but declined to give further details due to privacy concerns.
The Ethical Standards Command will investigate the shooting on behalf of the state coroner.
Queensland Police Union President Ian Leavers said Queensland Health should also be investigated for its role in events leading to Mr Angus's death.
"I understand this man had recent interactions with medical authorities for mental health issues and he was already back in the community," he said.
"I hope the health department are also investigated for their role and called to provide evidence to the coroner on their actions."
The ABC has contacted Queensland Health for comment.
Acting Chief Superintendent Lawson said the incident was captured on body-worn cameras.
"That footage will be available to the coroner and the Ethical Standards Command as they do their investigation," he said.
Acting Chief Superintendent Lawson said he was confident the officers involved "acted appropriately".
"Our use of force policy is very clear; that you use whatever use of force you consider necessary to resolve the incident," he said.
"At this stage, I'm confident in the briefings I've had, that the officers acted appropriately."
Acting Chief Superintendent Lawson said police had spoken to Mr Angus's family and that it was a "distressing time" for them.
"Obviously, our thoughts go out to the family involved because we don't want to see people being hurt and we don't want to see people die. We want to resolve these instances as peacefully as possible," he said.
Acting Chief Superintendent Lawson said support was being provided to the officers involved.
"There was an acting sergeant and a number of constables and senior constables there … they're people that do have some level of service but there are also people involved [who are] very junior."
"We've had to provide support to [all] those officers involved."
It comes just weeks after a 10-hour siege in the same suburb where shots were fired at nearby houses, a car and responding police vehicles.
Police found a man's body at a Kirwan home on March 13 after lengthy negotiations.
In another unrelated incident, police shot and killed Indigenous man Aubrey Donahue in Mareeba, west of Cairns, a month ago.
