A junior soldier has told a court martial he felt sick and flustered after his trainer hit his testicles and pulled on them.

Photo: RNZ / Kate Pereyra Garcia

Former staff sergeant Glen Edward Roberts has pleaded not guilty to 13 charges of ill-treatment of a person of lower rank, and also to assault and committing an act likely to prejudice service discipline.

The court martial was expected to hear from at least 20 witnesses.

A group of recruits joined the Army in 2014 and underwent their basic training at Waiouru Army Camp in the central North Island. Mr Roberts was their close-combat teacher there.

Five recruits have complained that while using them for demonstrations he went too far, hitting their genitals and pulling their hair.

Yesterday, the court martial heard from two recruits from the September 2014 training.

This morning, one soldier who trained in October 2014 said Mr Roberts "thrust" his fingers into his eyes when demonstrating how to get out of a hold.

He said Mr Roberts then asked the soldier to perform the hold again but, before he could, he "hit me in the testicles and pulled my testicles down".

The soldier claimed Mr Roberts then poked him in the eyes again, so hard his contact lenses fell out.

"I felt extremely sick and real flustered and, yeah, it hurt ... I never had anyone of a grown nature come and touch me like that."

He told the court martial he felt vulnerable and unable to complain because of the difference in rank between himself and Mr Roberts.

"I didn't really have the authority ... to step up at the time and say something was wrong."

During cross examination, defence lawyer Steve Taylor asked why the soldier had worn contact lenses during the training and why he did not tell Mr Roberts when they fell out.

The soldier said he felt too intimidated to raise it with Mr Roberts.

'Very aggressive'

A female soldier told the court martial that Mr Roberts was aggressive and threatened rape during simulated training.

She said he took hold of her hair, which was in a bun, and pulled her from side to side. Her hair ties and clips fell out, she said.

She recalled him saying "I'm going to rape you, white b**ch", while holding a rubber knife to her. "He was just very aggressive."

The same soldier recalled a second incident during the week-long training in which Mr Roberts pulled her along the ground and lay on her.

She said he wouldn't let her go until she grabbed his testicles. "I think my actual words were 'do you actually want me to do that' and he said 'yes'."

She was embarrassed and unsure if it was normal training behaviour, she said. "I wasn't sure as a recruit what I could do... I wasn't sure if I could react."

A third soldier told the court martial Mr Roberts also hit him in the testicles during a training demonstration. It hurt for about 30 seconds and he had stomach cramp, he said.

He said he enjoyed the training but felt they could have learnt without the physical strikes.

"[Mr Roberts] was a great instructor, sir, overall the course was very good."

Several other recruits from the October 2014 training platoon gave evidence today. Most agreed the training was good but they felt Mr Roberts went too far at times.

One private said he thought it was "pretty unnecessary".

"I wasn't so concerned about the rough treatment, I expected that, but just grabbing someone on the testicles and coming close to someone with a knife doesn't bode well with me."

Mr Roberts has been accused of using a real knife in training, when a rubber knife would normally be used.

One soldier gave evidence that Mr Roberts used a real knife to demonstrate ,and brought it within 8cm of another recruit's face.

Mr Roberts denied all the charges.

The trial continues at Linton Army Camp, near Palmerston North, before a panel of six military members.