Two Timaru policemen have been told by a judge their evidence was unreliable about why they Tasered and pepper-sprayed a man.

Timaru freezing worker Troy Duanne Hamuera Reuben, 36, was found not guilty of assaulting an officer in the execution of his duty by Judge Joanna Maze in Timaru District Court yesterday.

On December 29 last year police were called to Reuben's address after 11pm after a neighbour reported yelling and property being broken. When the first officer arrived a second man, said to be responsible for the disorder, was spoken to.

Then Constables Christopher Pritchard and Rory Chapman arrived and they went straight to the front door and entered, despite a boarder at the property telling them not to.

Chapman searched the house and did not find anyone, while Pritchard went into the bathroom where Reuben and a woman and child were showering in their togs, having just come back from the beach.

Both officers were then in the bathroom and claimed Reuben tried to throw the shower door at them. Pritchard then focused the Taser on Reuben, who along with the woman was yelling at the police to leave.

The officers alleged Reuben used the child as a shield as he went into the lounge and then lunged at Chapman, who then pepper-sprayed him, which also got in the eyes of a child in the room. Pritchard then fired the Taser at Reuben's back.

Judge Maze did not accept the lunge was an assault based on evidence from the Taser camera.

"The pushing or shoving of the shower door did not occur, the Taser camera shows it was still intact. Both officers are clearly wrong.

"Using the daughter as a shield is frankly nonsense. I do not accept the officers can be relied upon, given what they have said about both incidents," Judge Maze said.

"The footage shows the woman and man repeatedly asking them to leave, yet they remained while the child was screaming."

She believed Reuben had touched the constable's arm as he was gesturing for them to leave and that they did not have a license to remain as no-one was in danger. "The officers remained at their peril."

- © Fairfax NZ News