Victim describes alleged serial sexual abuse by school rugby coach Alosio Taimo

A young male witness has described feeling helpless and scared while allegedly being abused by a trusted mentor.

The-now teenager is one of 20 complainants accusing rugby coach and former teacher aide Alosio Taimo, 55, of sexual assault.

A video of a 2016 interview was played to the jury on Thursday morning in the High Court in Auckland, filmed when the victim was 13.

He claims the abuse started when he was 10 and would stay at Taimo's Auckland house.

"He would call me to his room with the oil and ask me to massage his shoulder, before pulling my hand towards his private parts," he said in the interview.

"I don't say no 'cos I don't know what he's capable of, I'm scared."

He told the interviewer "sometimes I just have to do it, quicker I do it, quicker I can leave. He won't stop until he gets what he wants."

The boy says not all the alleged abuse happened at the prominent community figure's house, and detailed how sometimes it took place on school grounds.

"He would call us into the PE shed. He would sit on a chair and I would have to stand and he would put his hands down my pants."

When asked how many times this happened, he paused before replying with "more than 20".

The jurors heard in the interview how the young boy would ask himself whether he was dreaming after each alleged assault, and that he often felt sick and in shock.

Taimo has pleaded not guilty to 83 charges in total, with incidents allegedly happening as far back as the 1980s.

Crown prosecutor Jasper Rhodes says the former teacher aide exploited his position of power and won the trust of parents.

But defence lawyer Panama Le'au'anae says the allegations are fabrication, and is casting doubt on claims Taimo could have got away with it on school grounds for so long.

The trial is set for 10 weeks.

Newshub.