An Indigenous Queensland man has died during a "violent struggle" with police that also left two officers with minor injuries.
Two other men are on the run after fleeing the scene of the incident in Toowoomba, west of Brisbane, about 12.30pm on Thursday.
Officers went to a street near the heart of the regional city after a member of the public reported seeing a group of people behaving suspiciously in a vehicle.
By the time officers arrived, they had determined the Subaru was stolen, Assistant Commissioner Mike Condon told reporters.
"Upon arrival police attempted to detain the occupants of the vehicle," he said.
Two men got away. The third died at the scene.
"During an altercation with police, a 27-year-old male person became unconscious, whereby police immediately provided first aid.
Paramedics arrived quickly and continued to work on the man but he could not be revived.
The incident is being treated as a death in custody and is being investigated by the police service's Ethical Standards Command, with oversight by the state coroner and the Crime and Corruption Commission.
"There mere fact that it was involved in an altercation will necessitate that we investigate the use of force used by our officers," Mr Condon said.
He would not comment on how the man became unconscious, but he did say there were witnesses.
"I would suggest that the fact there was a violent struggle would suggest that they were fleeing from the scene as they were in a stolen vehicle."
Mr Condon said the dead man's family had been notified and police liaison officers were working with the community "to ensure there are no concerns that may cause any unrest".
One of the police officers involved suffered breathing difficulties, and the other had minor, unspecified injuries. Both were taken to St Vincent's Hospital in satisfactory condition.
They are yet to be interviewed, but Mr Condon said that was likely to happen within 24 hours.
"The normal process is that they will stand down for a couple of days to regather themselves, but it really depends on the individual. But we are here to support them."
He said little was known about the dead man other than that he was 27, and a "First Nations person" born in the Western Downs town of Mitchell.
"We always try to expedite these matters to ensure the community have complete confidence in the investigation. We don't have all the answers at the moment.
"Until those investigations are complete, I would hope that common sense applies within the community, and we work together to ensure that once the outcome is known, that people will understand completely what's occurred."
The incident happened in Stone Street, Wilsonton. Police want to hear from anyone with mobile phone or dash cam footage.
Australian Associated Press