Secret findings from a probe into alleged Catholic abuse cover-ups in the NSW Hunter Valley have identified credibility issues among clergymen within the upper echelons of the church.

Key points: The once-secretive report raised credibility issues for two senior figures in the Catholic Church

The once-secretive report raised credibility issues for two senior figures in the Catholic Church After the Special Commission of Inquiry, Archbishop Philip Wilson was charged with concealing alleged abuse in the 1970s

After the Special Commission of Inquiry, Archbishop Philip Wilson was charged with concealing alleged abuse in the 1970s An abuse survivor says he is delighted the report has now seen the light of day

The Special Commission of Inquiry into allegations of a cover-up of child sexual abuse claims in the Catholic diocese of Maitland-Newcastle released damning findings in 2014.

At the time, only three of the four volumes of the report were released by Commissioner Margaret Cunneen SC.

The fourth volume included confidential material containing findings that the inquiry heard could lead to criminal charges being laid against a senior Catholic Church official.

That official was the former archbishop of Adelaide, Philip Wilson.

The commission heard allegations that in 1976, a 15-year-old altar boy, Peter Creigh, went to then-Father Wilson on two occasions and told him that four years earlier he had been abused by another priest, James Fletcher.

Mr Creigh told the commission he did not hear anything about the matter again and he held on to the allegations until coming forward to his family in 2009.

He said he told the then-bishop of the Maitland-Newcastle diocese, Michael Malone, about the abuse in 2010 before taking the matter to police in 2013.

Fletcher was charged in 2004 with other child sex abuse crimes and was convicted before dying in jail in 2006.

Findings raise credibility issues

The fourth and once-secretive report, now released by the NSW Government, raised credibility issues for both Archbishop Wilson and Bishop Malone.

"The commission formed the view that Archbishop Philip Wilson was an unsatisfactory and unimpressive witness in various respects," the findings said.

"Moreover, he gave certain evidence that the commission considered to be untruthful."

The commission formed the view that Archbishop Philip Wilson was an unsatisfactory witness. ( AAP: David Mariuz )

The commission also found the Archbishop was untruthful about his dealings with Fletcher and another deceased paedophile priest, Denis McAlinden.

It added that he was untruthful when speaking to another priest, Father Glen Walsh, who took his own life before giving evidence at subsequent court proceedings involving Archbishop Wilson.

"The commission also finds that during a meeting between Walsh and Wilson in July 2004, Wilson made an unprompted remark that he 'had nothing to do with' the Fletcher matter and nor did he have any information about it," the findings said.

"In view of its findings in relation to Wilson's knowledge about Fletcher, as conveyed by AM (a victim), the commission is of the opinion that the statement Wilson made was disingenuous and designed to mislead Walsh as to Wilson's true state of knowledge concerning Fletcher.

"Wilson gave other evidence that the commission considered to be self-serving and implausible.

"The commission formed the view that Wilson's evidence on contentious matters should be regarded with caution, except where it involved an admission against interest or was otherwise

corroborated by reliable evidence or contemporaneous documents."

Malone evidence 'implausible'

The commission also formed the view that Bishop Malone gave evidence in relation to Archbishop Wilson that was "unsatisfactory and untruthful in certain respects".

Michael Malone is the former bishop of the Maitland-Newcastle diocese. ( ABC News: Dan Cox )

"Malone gave evidence to the commission that was implausible," the findings said.

"It is improbable that the highly significant information relating to Wilson could, in reality, have been overlooked in the manner Malone suggested.

"Malone also gave untruthful evidence about his knowledge of whether Archbishop Wilson was a person of interest to the Strike Force Lantle [police] investigation.

"In response to a question about whether he understood Wilson to be one of the individuals the police were investigating, Malone replied, 'Not exactly, no. I wasn't sure who they were investigating'.

"Malone knew Gogarty was a complainant in the Lantle investigation and that Gogarty's complaint related to Wilson."

Wilson conviction quashed

After the Special Commission of Inquiry, NSW Police Strike Force Lantle charged Archbishop Wilson with concealing alleged abuse at the hands of Fletcher in the 1970s.

In May 2018, Local Court magistrate Robert Stone convicted him after accepting that Mr Creigh's memory of events was accurate.

The 69-year-old was the highest-ranking Catholic in the world to be convicted of concealing child sexual abuse and had been serving a minimum sentence of six months in home detention.

The judge took issue with inconsistences Peter Creigh made in his statements to authorities. ( ABC News: Jerry Rickard )

But in December, District Court judge Roy Ellis was critical of the Archbishop's conviction and quashed it on appeal.

Judge Ellis said Archbishop Wilson had been honest and consistent.

"There were very honest features of his evidence to provide a strong platform for him to be an honest witness," the judge said.

He said the Crown had failed to prove its case beyond a reasonable doubt and upheld the appeal, ordering the clergyman be released.

While Judge Ellis acknowledged that Mr Creigh gave an honest account, he questioned the accuracy of his memory given the length of time that had elapsed.

He also pointed to the evidence of memory expert Professor Richard Kemp who raised the potential for false memories.

"It is not inconceivable that in looking back, Mr Creigh convinced himself that he had complained, rather than asking himself why he didn't complain," the judge told the court.

His Honour also took issue with 12 inconsistences Mr Creigh made during his statements to authorities, including whether the conversation with Archbishop Wilson was before or after Easter, whether it was between 15 and 20 minutes or 30 and 40 minutes, or whether he referred to Archbishop Wilson as "Philip" or "Father Wilson".

"The inconsistencies neither individually nor in combination prove that the alleged conversation did not take place, but they are capable of raising reasonable doubt," the judge said.

Peter Gogarty says he is delighted to have the findings of the report. ( ABC News )

Abuse survivor relieved

Hunter Valley abuse survivor Peter Gogarty said it was a huge relief to finally have the report.

"We've been through a prosecution process with the former Archbishop Philip Wilson that resulted in finally an acquittal on appeal, but I think what this report does is says that the person who made that complaint against Wilson, that person was credible," he said.

"So I've got no doubt that people in the Catholic Church would not have wanted this report to have seen the light of day. I'm delighted that it has.

"I have a fear that, even after the royal commission, I'm not sure that people in high places in the Catholic Church have genuinely tried to change their behaviour and get this right."

Report conclusions 'disturbing'

NSW Greens MP David Shoebridge said the report was damning of the church and two of its most senior officials.

"The conclusions the report draws about the knowledge of former bishops Wilson and Malone concerning child abuse allegations are disturbing," he said.

"At a minimum, the church must now admit that it had detailed knowledge of the activities of predatory priests and failed to act, leaving children at their mercy and destroying young lives.

"It is a matter of record that Bishop Wilson was acquitted on appeal for the criminal charges against him, however this cannot allow the church to escape from the consequences of this report."