The car, driven by the accused's partner, was initially waived through a checkpoint, but subsequently stopped for a breath-alcohol and licence check.
Mrs Sheridan said Neilson become enraged when told his partner's car was being impounded because she was driving on an expired licence. Due to his behaviour, other police officers became involved.
Neilson was arrested for possession of knuckledusters. He refused to allow the three or four officers to handcuff him and, during the ensuing struggle, was physically restrained on the ground, and had to be carried and pushed into the patrol car.
Mrs Sheridan said that at the station Neilson complained about excessive force and a police doctor who examined him treated him for a small abrasion on his forehead.
The next day Neilson returned to the station with more injuries to support his complaints, which he made to police officers, the police doctor and his neighbours. Each time the allegation was significantly different, Mrs Sheridan said.
"At one time he said he was violated with a torch, other times it was a finger, a pen, then a pencil." she said.
Mrs Sheridan said the complaints were thoroughly investigated and found to be false.
Neilson told his own doctor his injuries occurred during a boxing match and made no mention of a police assault, she said. Police admit several punches were needed to restrain Neilson but the officers deny there was any sexual connection or other assaults.
Suppression orders prevent the Bay of Plenty Times revealing the identities of the three police officers at the centre of the prosecution case.
The trial is expected to take seven days.