Officers were justified in the use of force in arresting two men who fled from a crash scene, one of whom choked a police dog unconscious, an investigation has found.
But the Independent Police Conduct Authority (IPCA) said the actions of one officer in presenting a Taser at a handcuffed man was not justified.
The IPCA has released its report into the pursuit of a fleeing driver in Waikato on February 28, 2013, finding police actions mostly complied with policy.
The incident began after a speeding Holden Commodore failed to stop for police and was pursued at high speeds for seven minutes.
Just as officers were given the order to abandon pursuit, the vehicle went over road spikes laid on State Highway 1 at Tamahere, spun off the road and crashed. The two occupants fled.
Following police cars also went over the spikes, which had been flipped upside down by the speeding Holden, the report said.
One officer told the IPCA his first thought as he hit the spikes was: "Crap, I hope that's not a body".
Police were aware the car was associated with a man wanted for aggravated robbery and believed to be in possession of firearms. The other man in the car was wanted by police in relation to armed robberies.
Officers were advised to arm themselves, and two dog handlers, one carrying a Glock pistol, were sent to track them.
One man was found in a truck cab in a nearby truck yard, and was bitten by a police dog during a struggle with the officers, but managed to cross a drain and climb a fence to escape.
The police dog was put over the fence to chase him, and when an officer found the man a short time later he had choked the dog unconscious.
The officer said he believed the dog was dead, and assumed the offender must have had a weapon.
He fired a warning shot, and then two officers struggled to subdue the man until a third arrived and helped handcuff him, the IPCA report said.
Another officer drew his Taser and pointed it at him as he was being taken, handcuffed, to a location where an ambulance could reach them.
The second man was arrested by Armed Offenders Squad members after being found by the police helicopter.
He claimed he had been shot by police, but a police doctor found his wound was not caused by a bullet, and there was no evidence of a shot being fired.
The first man suffered extensive bite wounds, and claimed police hit him in the eye socket with a torch or baton. The authority found there was no evidence of this.
Chairman Judge Sir David Carruthers said police were responding to a complex situation. He said the officers were justified in pursuing the two men, arming themselves, deploying police dogs, and firing a warning shot.
However, officers were not justified in presenting a Taser for 18 minutes when the offender was handcuffed and no longer resisting.
Police communication should also have been clearer during the incident, Sir David said.
No recommendations were made.