A former police sergeant criticised twice in just over three months by the Independent Police Conduct Authority (IPCA) has left the police.

In its latest finding, the IPCA ruled an unnamed sergeant breached policy by ordering a probationary constable to Taser a Greymouth man. The Taser use was unjustified, the IPCA said.

The Westport News has confirmed the sergeant was Matthew Frost, who has previously been the subject of two internal police investigations.

Tasman District commander, Superintendent Steve Kehoe accepted the IPCA's findings and said the sergeant had resigned from the police force.


Frost had been a policeman for 28 years, including 11 years as a sergeant. He transferred to Westport from West Auckland in 2007 and to Greymouth about three years later.

In 2014, while off duty, Frost crashed his car on State Highway 6 near Punakaiki. He later told police he had downed six beers and three whiskies beforehand, but thought he was okay to drive.

He was never breath tested because police didn't track him down for two days.

"He didn't report it at all, we actually caught up with him," then West Coast commander Inspector John Canning said in 2014. "He actively avoided us, basically."

Frost subsequently admitted a charge of careless driving and was convicted and discharged.

In May last year, Greymouth police detained three people for questioning at the Greymouth police station.

The IPCA subsequently ruled the police officers had seriously breached their prisoners' rights. It described the actions of an unnamed sergeant as "a flagrant abuse of his power".

The IPCA said the sergeant was not justified in arresting or charging a man with possessing cannabis and should have advised the man his lawyer had called. The sergeant was not justified in directing officers to keep the man and a woman in custody for periods of over 15 hours and 19 hours respectively, and another man in handcuffs for almost nine hours, the IPCA ruled.

The Westport News subsequently confirmed the sergeant was Mr Frost.

Taser breach

In its latest finding, the IPCA said the sergeant should not have directed a probationary constable to use his Taser. Firing the Taser twice to stun a Greymouth man amounted to "disproportionate and unjustified use of force".

The IPCA report said that when the sergeant filled out an operations report, he did not include that he had been present when the Taser was used or that he had directed the constable to use it.

He also incorrectly recorded that the Taser use complied with police policy.

The report said Greymouth police were called to a domestic incident between Greymouth neighbours at about 9pm on June 20, 2015.

A drunk 44-year-old man had gone to his neighbour's house armed with a tomahawk, after becoming upset by the noise from a party.

A partygoer managed to wrestle the tomahawk off the man. When police attended, they were told that the man was no longer armed and had gone back home.

Greymouth police were aware of the man and his mental health issues. Police decided to delay arresting him until he had sobered up the next morning, the report said.

However, police were called back to the man's property at midnight. Officers found the man, and his friend, drunk and abusive, sitting in a car. They arrested the man for the tomahawk incident, but he and his friend refused to get out of the car.

After a 20-minute struggle, during which police appropriately pepper sprayed the friend with little effect, they managed to handcuff both men and escort them to a police van, the report said.

When the man refused to move his foot from the van cell door, the sergeant directed a probationary constable to stun the man twice with a Taser.

The constable was reluctant to do so, because the prisoner was being non-compliant rather than assaultive. However, he thought the experienced sergeant knew best.

The sergeant told the IPCA he believed the use of the Taser was lawful, and posed the least risk of injury to the man and police. When asked why he didn't use the Taser himself, he told the authority he had not signed out the weapon or done pre-operation safety checks.

The report said the first tasering didn't work. The Taser was fired again and the man removed his foot from the door.

The man did not make a complaint and would not be interviewed by the IPCA. His lawyer prepared a statement on his behalf for police.

His denial of being angry, aggressive or threatening was at odds with the evidence of the three police officers.

The man subsequently pleaded guilty to possessing an offensive weapon and was convicted and fined. A charge of resisting police was withdrawn.

IPCA chair Judge Sir David Carruthers said a Taser could only be used on a person who was assaultive.

"As the man was simply using his foot to block a door, he was not assaultive. The Taser should therefore not have been used."

The sergeant should not have directed the probationary constable to use the Taser.

"The junior officer was put in the unenviable position of feeling like refusal was not an option, given the sergeant's seniority," said Sir David.

The IPCA report said the sergeant should have declared that he had instructed the probationary officer to use the Taser. The sergeant's report had incorrectly recorded that the use of Taser complied with police policy.

Mr Kehoe said police agreed the use of Taser was unjustified and the sergeant should not have directed an inexperienced officer to stun the man with the Taser.

"We understand the pressure felt by the probationary constable to follow their supervisor's orders and have provided advice around this matter to them."

The IPCA's report is the third in just over three months to criticise West Coast police.

In October last year it found a Hokitika officer's use of a Taser on a mentally unwell Hokitika man in April 2015 was "disproportionate and unjustified".

- Westport News