The Independent Police Conduct Authority has found that a South Auckland sergeant's use of a Taser on a mentally unwell man at the Counties Manukau Police station was "contrary to policy, excessive and unjustified".
Police were called to a South Auckland address on April 27 last year after a 111 call about a man wielding a large knife and threatening to self harm.
When police arrived, the man's family told them he had been cutting himself earlier in the day with a small pocket knife and that it was possible he still had this knife concealed on him.
Officers arrested the man for possessing an offensive weapon and took him to the police station. He was told he would be strip searched and was taken to a small cubicle to wait for officers.
He refused to remove his clothes and police advised him that if he did not, they would cut the items off him.
As they tried to remove his clothes the man resisted.
A sergeant entered the cubicle and used a Taser twice on the man, his actions caught on the room's CCTV camera.
The Tasering was reported to the IPCA, which investigated and released its findings today.
The authority viewed footage from the camera in the custody suite and footage taken from the Taser camera.
"Police policy clearly states that a Taser must only be used on a person who is assaultive. As the man was being held down by two officers and had his back turned to the sergeant when he was Tasered, his behaviour had not met that threshold," said authority chairman, Judge Sir David Carruthers.
"The sergeant's use of the Taser breached police policy and was excessive and unjustified.
"There were other, less violent, options available to the officers.
"They could have continued communicating with the man or have asked the officers who were outside the cubicle for assistance."
Police this morning said they accepted the IPCA's finding.
They said police had twice dealt with the man that day, once in Waitakere and once in South Auckland where he was threatening to harm himself.
They said the man received appropriate medical care.
Counties Manukau police operations and support manager Acting Superintendent Tracy Phillips said the man's behaviour was unpredictable throughout the day.
"It is always a challenge to deal with people suffering from health issues when we don't have all of the information," she said.
"Police accept the incident could have been handled differently for a better result for all involved.
"Our officers find themselves in difficult situations on a daily basis and have to make hard decisions with the information available to them at that time.
"We completely accept the IPCA's findings and will be taking this as a learning opportunity."
Phillips said police also did an internal investigation.
As it was an employment matter, she could not elaborate on the investigation or the outcome.
"A number of lessons have been identified from this case and we continue to provide training and constructive feedback to help inform decision-making and judgment with our staff," she said.