The response within the diocese of Ballarat to abuse complaints spanning at least three decades was driven by a desire to avoid scandal and protect the church's reputation, the report by the Royal Commission into Institutional Responses to Child Sexual Abuse found.

The findings, which come a day after a similarly damning report about the Melbourne archdiocese was released, said "commissioners heard that there was a tendency by clergy in the Diocese to treat complaints or allegations of child sexual abuse dismissively and in favour of the priest who was the subject of the allegation".

As with the Melbourne findings, much of the report is redacted and makes no findings on the conduct of Cardinal George Pell.

The commission said on Tuesday that its terms-of-reference prevent the release of information that could "prejudice current or future criminal or civil proceedings".

Page 161 of the Ballarat report reveals that "Father Pell was described by one former St Patrick's College student as someone who he thought might one day be Pope".

This is followed by 12?? pages of redacted material.

Priests were moved to another parish if allegations emerged where they often offended again.

The inexcusable failures led to more children being sexually abused by Catholic clergy in the diocese.

"That failure led to the suffering and often irreparable harm to children, their families and the wider community," the commission said in its report released on Wednesday.

"That harm could have been avoided if the church had acted in the interests of children rather than its own interests."

It pointed to Bishop Ronald Mulkearns' extraordinary and inexcusable failure to act on a mother's concerns about her son living in a Mortlake presbytery with priest Gerald Francis Ridsdale, who he knew had abused boys.

"Bishop Mulkearns again was derelict in his duty in failing to take any effective action to have Ridsdale referred to police and to restrict Ridsdale's contact with children".

In response to the specific case of Paul Levey, who lived with Ridsdale at the presbytery in Mortlake, the commission described Bishop Mulkearns' response as "appalling".

"The most likely explanation for the conduct of Bishop Mulkearns and other senior clergy in the diocese was that they were trying to minimise the risk of scandal and protect the reputation of the Catholic Church", the report said of Bishop Mulkearns' response.

The Christian Brothers operated and provided staff to six primary and secondary schools in Ballarat and Warrnambool, which included some of the country's most notorious paedophiles.

Ten men provided evidence of sexual abuse at St Alipius Christian Brothers School, while a further seven who were abused at St Patrick's College also spoke.

The report described the response to allegations of sexual abuse from the group as "grossly inadequate", and said brothers were regularly shifted to a new location after an allegation had been made.

Among those was the case of Brother Gerald Leo Fitzgerald, who died in 1987 before any charges were laid against him.

For 12 years until 1975, Brother Fitzgerald worked at St Alipius, where complaints were made against him.

Despite senior Christian Brothers figures knowing of allegations, he was shifted into retirement on the Brothers' residence at the St Patrick's College, where he continued to have access to children.

The commission also found "each year, Brother Fitzgerald took grade 3 boys swimming naked at an annual St Alipius camp," and that "the practice was notorious among students at St Alipius and St Patrick's College".

The commission heard reports from several victims who claimed to have been sexually abused by Brother Fitzgerald while at St Alipius.

The commission's investigation exposed a catastrophic failure in the church leadership and ultimately its structure and culture over decades to properly respond to its priests abusing children.

"There was a catastrophic institutional failure which resulted in many children being sexually abused by Catholic clergy in the diocese," it said.

"The response primarily revealed a desire to prevent or minimise the risk of scandal and to protect the reputation of the Catholic Church."

The Royal Commission into Institutional Responses to Child Sexual Abuse also said former Ballarat bishop Ronald Mulkearns and other clergy were dismissive of complaints and victims.

The Courier, AAP