A constable who claims to have seen his sergeant kick a prisoner in the groin says he wondered whether that was just "the way things are done in west Auckland".
Sergeant Martin James Folan has pleaded not guilty in Auckland District Court to six charges of assault and one of injuring with intent to injure.
One of the more serious allegations is that Folan kneed a man in the groin, causing him to lose a testicle.
Giving evidence today, Constable Scott Sherer said he saw Folan kick another prisoner, Samuel Verdonk, when he was in a cell in the Henderson Police Station.
Mr Sherer said Folan planted a hard kick to Mr Verdonk's groin and lower stomach after officers entered the cell to restrain the prisoner because he was banging his head on the walls.
Mr Sherer had recently been transferred to Henderson Station from the North Shore, which he said had been a big change.
"I was getting used to the way things were done in west Auckland, I was getting used to the change, but I remember that moment (when he saw the alleged assault) thinking 'wow, is this the way things are done in west Auckland?' Of course, that went against my understanding of general police professionalism."
Folan's lawyer, Richard Earwaker, said his client would testify he had only used the ball of his foot to push the prisoner off balance because he had rushed at the officers.
Also testifying against her senior officer, Constable Bryony Brown said she saw Folan knee heavily intoxicated prisoner Joseph McGee - who she remembered as "the man making animal noises" - as he was being processed.
"I saw a knee come up from Sergeant Folan into the lower abdomen area, I saw it very clearly.
"It was super quick... it seemed like there was some strong force behind that knee."
The constable was adamant about what she had seen, despite rigorous cross examination from Mr Earwaker, who argued her view would have been obscured by a partition to the cubicle where the alleged assault happened.
Mr Earwaker also put to her that she was "browbeaten and pressured" by the inspector who interviewed her about the incident, and was influenced by "Chinese whispers" circulating around the station.
Constable Frank Grieve, who was Acting Sergeant that night, told the court he and Folan had disagreed about how Mr McGee should be handled. He had argued the prisoner should be put straight into the cells and not be processed immediately because he was extremely intoxicated and uncooperative, but Folan had thought otherwise.
"There was no advantage to having a man held by force in the corner of a cubicle for an extended period of time to get details that we already had.
"I thought it was putting people in danger," Mr Grieve said.
But the sergeant yelled at him to "fill out the charge sheet" and took the prisoner to the processing area where the alleged assault took place.
Mr Earwaker said Mr Grieve had acted out of rank and should have left it to the more senior officer to do his job.
Another officer, Constable Daryoush Farhani, told the court he saw Mr McGee writhing around on the floor of his cell in pain, holding his groin.
He was covered in vomit and could not walk, Mr Farhani said.
The constable said he told Folan the prisoner was in a lot of pain, but the sergeant just shrugged and did not call a doctor.
Mr McGee's testicle was subsequently surgically removed.