THE police ethics committee is investigating the circumstances surrounding the death of man at Shute Harbour yesterday morning.
He drowned, despite officers' best efforts to rescue him.
The 51-year-old was wanted for questioning by Whitsunday police in relation to an alleged assault on a private boat moored at Shute Harbour about 4.30am yesterday.
Acting on information received, officers went to Shute Harbour about 9.30am yesterday, Acting Inspector Gary Green said yesterday.
They sighted the man in a rowing boat on the water, he said.
When they called for his attention from the shoreline, he stood up in the boat but showed no signs to moving towards police.
Acting Insp Green said the man then jumped into the water.
Officers continued their attempts to communicate with the man, who was observed holding onto the side of the boat.
"Police then saw him go under," Acting Insp Green said.
Two officers immediately swam out to rescue him, however, the man was unconscious when they reached him.
The two officers pulled the man back to shore and commenced CPR until paramedics arrived, Acting Insp Green said.
The man could not be resuscitated; he died around 10am, he said.
A Queensland Fire and Rescue Service crew was called to help with the retrieval of the body, which had been brought to a mangrove area for officers to commence CPR.
Firefighters attached a guide rope to their vehicle, which was parked on Shute Harbour Rd at the bend just before the Shute Harbour Motel.
This was then attached to a stretcher, which was used to retrieve the body.
A Queensland Police spokesman said yesterday the Queensland Police Service Ethical Standards Command would attend and take charge of the investigation, which would be overviewed by the Crime and Misconduct Commission.
A report will also be prepared for the Coroner, Acting Insp Green said.
The man had only been in the area for a few weeks and was living on a yacht in the nearby area, Acting Insp Green said.
The attending officers had concerns for the state of the man's mental health, he said.
The man wasn't known to local police.