The former Maitland-Newcastle Vicar General - the number two cleric in the diocese - complains about being perceived as "the bad guy" in the second episode of the ABC series on the Catholic Church, Revelation, screening tonight, about the teenager's death in October 1974 and child sexual abuse at Hunter Catholic schools.

"Look, I've had enough of Andrew Nash, really. Absolutely. You know, the whole thing has turned... I went out and anointed him and I'm the bad guy. Why? I don't know," Father Burston said about the night of Andrew Nash's death, when he went to the Nash home with priests and Marists who would later be jailed for child sex offences, including Brother Romuald and Brother Christopher.

Father Burston insists Andrew Nash's suicide at home was a "prank gone wrong" and denies the teenager was sexually abused by Romuald, his Marist Hamilton year leader. This is despite the Marist order and Maitland-Newcastle diocese accepting the teenager's suicide and sexual abuse by Romuald, who has been convicted of sexually abusing 24 boys.

"I think it was a prank gone wrong. I honestly do. And I'm not blaming him for that, I'm not, but yeah," said Father Burston nearly five years after a church-commissioned panel recommended he resign or be stripped of his right to ministry. This followed findings he "manifestly failed" to give honest evidence at a child sexual abuse inquiry into notorious Hunter child sex offender priests Denis McAlinden and Jim Fletcher in 2013.

In the Revelation interview with ABC veteran journalist Sarah Ferguson Father Burston recounts one of three stories circulated by Marists and priests to the community and Marist Hamilton students immediately after Andrew Nash's death - that the teenager hanged himself while playing hide and seek with his sister Bernadette.

"I feel sick in the guts about what he said. I was eight years old. I only found out recently that that was being said about me. It's destroyed my life," Bernadette Nash said.

She wept on Monday as she, her mother Audrey, 94, and brother Geoffrey demanded Maitland-Newcastle Bishop Bill Wright immediately remove a statement from the diocese website defending Father Burston's "impressive ministry" and "significant contribution" to the diocese after his appearance on the first episode of Revelation.

They have also demanded Bishop Wright act on the 2015 recommendation that Father Burston be stripped of his right to ministry. Father Burston's resignation relieved the bishop of the need to publicly discipline the priest who has continued to say mass and preside over church rites across the Hunter, including baptisms and funerals. This is despite being described by the diocese as "retired".

"Burston's words are cruel and hurtful, disgraceful and abhorrent. What he says is not true. There was no game and no prank on that night. Andrew was raped and tortured to the point where he killed himself rather than go to school," said Audrey Nash.

"What Burston said on a national television show is behaviour unworthy of a priest. The Catholic Church, the bishop and the diocese's Office of Safeguarding should do their job and dismiss Burston from the priesthood."

Geoffrey Nash, who was 17 when he found his brother's body in a bedroom, said Father Burston's statements and the diocese's public support for him last week made previous apologies and acknowledgments "meaningless".

"Some bulls... apology from the diocese isn't enough this time. It's 2020, four years after the Marists apologised at the royal commission, and here's the former Vicar General, the number two man, and he's still going. He's still blaming the children. He still persists with these outrageous claims. At least we know this is what they actually think," Mr Nash said.

"Andrew was a little altar boy who went to the church three times a week. He loved going to church. He trusted the Brothers and the priests. The first time Burston met Andrew was when he went into the bedroom in 1974 and saw his body."

In the Revelation interview Father Burston said a coroner's "open verdict" about Andrew Nash's death had "unfortunately been tainted by much later understandings of stuff that I think are not accurate enough".

Audrey, Geoffrey and Bernadette Nash slammed Father Burston's description of coroner Reginald Radford's finding on December 19, 1974 that "'Whether (Andrew) died accidentally or otherwise, the evidence adduced does not enable me to say''.

A finding of suicide in 1974 would have made Andrew Nash one of the youngest people recorded in Australia to have taken his own life.

In a Newcastle Herald interview in 2015, nearly 18 months before the Marist order accepted Andrew Nash was sexually abused and committed suicide, Mrs Nash said she believed her son took his own life.

Mr Radford was simply unable to deliver a suicide finding at an inquest where the only people in attendance were a grieving Catholic mother and her surviving teenage son, she said.

Mr Nash said the diocese had repeatedly acknowledged its failure to provide any support or care for the Nash family after Andrew's death, but its praise of Father Burston last week after Revelation's first episode was deeply hurtful and perpetuated the prioritising of priests' needs over child sexual abuse survivors and their families.

"It's not an each-way bet. You can't say sorry to Audrey and stick up for Burston in the way that they have," Mr Nash said.

In the statement the diocese said Father Burston "remains a respected priest for many".

It quoted a 2013 inquiry finding that Father Burston was "an unimpressive witness in certain respects" about knowledge of Denis McAlinden and Jim Fletcher allegations, but did not include any reference to a later church-commissioned investigation which recommended he be stripped of his ministry.

''It is clear from the transcript that the 'certain respects' referred to by the commissioner were not limited or isolated, but related to significant and extensive parts of Father Burston's evidence,'' the investigation panel found

Father Burston's continued public ministry had been ''fatally compromised by his evidence before the commission and its findings'', the panel found.

Audrey Nash said the family was exhausted by years of Andrew's death being misrepresented and silenced "as if Andrew never existed", and at 94 she felt like the Catholic Church was playing a waiting game with her.

"I can hear them saying 'When is she going to die, the old lady?'" Mrs Nash said.

Geoffrey Nash said the family would not rest until the Catholic Church's responsibility for Andrew Nash's sexual abuse and death was finally and fully accepted, and the awful truth absolutely acknowledged.

"Until Audrey takes her last breath she's going to fight for justice for her little boy and little girl," he said.