A teenage boy, one of nearly 20 accusing an Auckland school rugby coach of sexually abusing them, says the teacher aide "won't stop until he gets what he wants".

Alosio Taimo, 55, is facing 83 charges against 18 then-young boys — some going back to the late 80s and early 90s.

The alleged offences took place at his home, in his car, in school sports sheds, in a classroom, and in a South Auckland park from 1987 to 2016.

Initially, there were nine complainants and 53 charges against Taimo, an experienced teacher aide, rugby coach and sports manager.

However, after the Herald and other media published his name more complainants came forward.

Taimo denies all the charges against him and his defence says the allegations are "lies" and a "fabrication".

Today, Taimo's High Court jury watched the first complainant's police interview from August 2016.

He was 13 at the time.

Sitting in a blue and grey interview room, he said he was there to talk about "being a victim" and "getting touched in a sexual way" by the man he called Mister.

Taimo's alleged offending first came to light when one boy's aunties overheard him "talking to other children about what had happened", Crown prosecutor Jasper Rhodes said during his opening address yesterday.

The woman rang her son who said: "Yes Mum, it happened to me too."

Talking to police while still wearing his school uniform, the first complainant said Taimo abused him after picking him up and taking them to his South Auckland home.

"[He] calls us to his room, calls me to his room, and he starts touching me," he said.

"He says 'get the oil' and stuff to do the massage."

The teen said Taimo would pull his hand towards the older man's groin.

"I didn't want to say no, 'cause I didn't really know what he was capable of," he said.

"The quicker I do it, the quicker he'll let me go. Cause if I don't do it he's just going to keep me there.

"He won't stop until he gets what he wants."

The court has heard several of the boys were allegedly violated in a school sports shed during lunch breaks.

"He calls us to the PE shed ... me and my friends, but sometimes he just calls me," the teen told police.

Some of the schoolboys talked to each other, he said, about what happened in the sports shed and in Taimo's car.

Taimo's trial began on Monday in the High Court at Auckland and is expected to last 10 weeks.

He faces 24 charges of sexual violation by unlawful connection, 18 charges of an indecent act on a child under 12, 23 counts of an indecent act on young person under 16, eight charges of indecency with boy under 12, and 10 charges of indecency with a boy between 12 and 16.

The jury will be asked to return verdicts on each individual charge.

Suppression orders prevent the Herald from naming any schools or sports clubs associated.

The trial continues.