Former brother of St John of God, Bernard McGrath, will be eligible for parole in December 2044.

McGrath, who is serving two prison sentences in NSW for sex crimes against children, says his religious order and the Catholic Church covered up his offending at schools in Australia and New Zealand.

In the early 1990s, after decades as a sex offender, new reports emerged about McGrath's abuse of children at schools and a residential program he'd run for street kids in Christchurch, New Zealand.

Following Catholic Church protocol, the head of St John of God in Australia took McGrath to meet Father Brian Lucas.

A priest and civil lawyer, Lucas was head of the Catholic Church's Special Issues Resource Group, tasked with the church's response to the emerging scandal of child sex abuse by Catholic priests and brothers.

In an interview for the ABC series Revelation, McGrath says he told Lucas at their meeting that there would be further complaints of sexual abuse against him: "I told him I had offended ... And I can remember him saying, 'Would there be others?' and I can remember saying 'Yes'."

Priest and civil lawyer Brian Lucas has defended his handling of some of the Catholic Church's worst paedophiles. ( Revelation/In Films )

Lucas acknowledged the meeting took place but said he could not remember the details of the exchange.

He also said he was not obliged to report McGrath to police: "Not when that conversation is premised on the basis that he has a right to silence and this conversation is confidential," Lucas said.

"His order could have handed him over to the police. He could have given himself over to the police. His victims could have gone to the police."

Sent overseas for 'treatment'

Despite McGrath's admissions, Lucas rejected the suggestion that by not reporting McGrath to police he had engaged in a cover-up. "You might call it a cover up... I don't accept that," he said. "We're in a situation of a confidential conversation."

Lucas has long defended his handling of some of the church's worst paedophiles, saying it was his job to encourage priests or brothers to leave the church.

"What you can do is to entice him out of ministry with a view that in due course the criminal justice system will kick in," said Lucas, claiming that he had no obligation to help the justice system pursue McGrath.

McGrath's two most recent trials in 2018 and 2019 saw him receive concurrent sentences that mean he will most likely die in jail. ( Revelation/In Films )

Bernard McGrath said that Lucas raised the prospect of "treatment" to address his abuse of children. When questioned, Lucas could not give any example of a paedophile who had been successfully treated.

"Some may not be cured, but some may learn how to manage their behaviour," Lucas said.

Following the meeting, the head of the order, Joseph Smith, took McGrath out of Australia, accompanying him personally to a Catholic treatment facility in Jemez Springs, New Mexico.

The facility was run by a Catholic order named the Servants of the Paraclete. Their services included a treatment course for paedophile priests and brothers.

At least one other prolific Australian paedophile was sent to Jemez Springs: notorious Victorian offender Gerald Ridsdale, who spent time there prior to his arrest in 1993.

Decades of cover-up

The cover-up of McGrath's crimes began more than 20 years earlier. At the Marylands School in Christchurch, McGrath claims he kept his offending hidden.

"Like anybody who offends. You don't tell people ... It becomes that secret inside you which becomes a cancer," McGrath said.

Sean Buckley was a New Zealand detective who investigated McGrath's crimes in Christchurch. He described his methodology at the school.

"He's very manipulative," Buckley said of McGrath. "He had a small group of older boys who had all been his victims and he was able to manipulate them into ... going out and getting younger boys."

A student at Marylands, St John of God school in Christchurch. ( Revelation/In Films )

In 1977, reports of McGrath's abuse at Marylands reached the head of the order of St John of God in Sydney, Brian O'Donnell. O'Donnell responded by moving McGrath to another school run by the order in Australia.

"I got the 'obedience' to move and I moved," McGrath said. "My hunch was because I had offended."

New Zealand detectives were angry that St John of God could have moved a suspected paedophile to run a school in Australia.

"The order knew exactly what was going on," Detective Buckley said. "Instead of dealing with it, they shifted the problem on, which is what we've seen around the globe." So instead of there being "five or six victims, just at Marylands", he said, "it escalates and now we're looking at ... hundreds of victims".

McGrath was not the order's only offender

In late 1977, McGrath went to Kendall Grange, a boarding school on the shores of Lake Macquarie. He became headmaster in 1980.

He has since been convicted of abusing 28 children at the school, including multiple counts of oral and anal penetration. Police believe there are many more victims who have not yet come forward.

Survivor Paul Andreassen said McGrath (pictured), then headmaster of Kendall Grange school, groomed him by giving him cigarettes and sweets. ( Revelation/In Films )

Aged 11 at the time of his assault, Paul Andreassen described how McGrath had groomed him by letting him drive the school bus and giving him cigarettes and lollies.

"The worst was where I was in a bedroom, and he put his penis between my legs, and proceeded to ejaculate," Andreassen told the ABC.

Kendall Grange, like Marylands, was a special school for boys experiencing family or educational difficulties.

"A lot of us, we had nowhere else to go but Kendall Grange. That was our last hope," Andreassen said. "It was either you had troubles at home or at school or both."

Another man called Paul was raped by McGrath at the school. He was only 9 years old when Brother Bernard began abusing him.

"It's like they rape your soul," he said. "I feel like my soul's not there. I feel numb ... hate is no good. Hating only just eats you away. But I don't love real good, I find it hard to love people."

McGrath was not the only offender in the order. The Royal Commission into Institutional Responses to Child Sexual Abuse found that 40 per cent of the order's members were alleged to have been sex offenders since its foundation in Australia in the 1950s.

In the early 1990s after his "treatment" in New Mexico, McGrath chose to return to Australia. Since then, he has not been able to escape the law.

His two most recent trials in 2018 and 2019 saw him receive concurrent sentences that mean he will most likely die in jail.

Paul, one of McGrath's victims said: "There's a lot of other people out there that can't even speak, let alone speak up for what happens to them in them places. I don't know how them brothers can sleep in the night."