Marist ignored allegations that a now notorious paedophile teacher was sexually abusing students, instead shuffling him between schools, in one case even promoting him to principal, and failing to refer complaints to police, the royal commission has found.
The Royal Commission into Institutional Responses to Child Sexual Abuse delivered its formal findings on the cases of Brother John Chute, also known as Brother Kostka, and another Marist brother, Gregory Sutton, on Friday.
The pair abused students for decades at a string of schools across Australia, including many at Marist College Canberra.
When allegations child molestation surfaced, they were handled woefully, with the brothers simply moved between schools, given warnings, or placed under "supervision".
The failings allowed the pair to continue to access and abuse vulnerable children, the royal commission found.
Marist victim and anti-child abuse campaigner Damian De Marco welcomed the Royal Commission's findings on Friday, describing the depth and length of Marist's knowledge of the abuse as "staggering".
Mr De Marco said the examination of Marist, used by the royal commission as a case study, showed a clear pattern in the Catholic Church's response to abuse.
Marist's actions, he said, were motivated by self-protection at the expense of victims.
"They forgive the perpetrators, silence the victims, and then traffic the perpetrators somewhere else," Mr De Marco said.
"The Marist case study is just a microcosm of the broader organisation and the bigger problem."
Marist failed to refer child sexual abuse complaints to police between 1962 and 1993, the royal commission found, and no written records were kept about the allegations that were made, or the transferring of Brothers Kostka and Sutton between schools.
The case of Brother Kostka is marked by repeated instances in which teachers or "provincials", senior Marist figures with responsibility for the brothers, ignored allegations of child sexual abuse.
Brother Kostka arrived at Marist College Canberra, the last school of his career, in the mid-1970s.
When he finally left the school in 1993, 48 of his former students came forward with claims of abuse.
Forty of those were from Marist Canberra.
Marist Brothers has paid out $6.8 million to Brother Kostka's victims.
Decades before he came to Canberra, Marist were made aware that Brother Kostka was abusing children at schools in NSW and Queensland.
Kostka himself had made admissions about touching a child in the 1960s.
Two provincials, Brother Othmar Weldon and Brother Alman Dwyer, decided to give Brother Kostka a "canonical warning" in 1969 after he admitted to touching a child at a Lismore school.
Inexplicably, he was subsequently transferred to a school in Penshurst and promoted to principal.
Neither Brother Weldon or Brother Dwyer passed on the information about Brother Kostka's abuse to their successors.
"That neither Brother Weldon nor Brother Dwyer ensured this conduct was known by subsequent provincials meant that no warning was given to prospective schools of the risk Brother Chute posed to children and reflects very poorly on the Marist Brothers' approach to these matters under the leadership in place between 1958 and 1972," the royal commission found.
In 1986, the then provincial, Brother Dwyer, was told of an allegation that Brother Kostka had touched a boy's penis at Marist Canberra.
He did nothing, despite already knowing of Brother Kostka's admission in the Lismore case.
Brother Kostka continued to teach at Marist Canberra. The next brother to serve as provincial, Brother Alexis Turton, was also made aware of a complaint of molestation in late 1993. Brother Kostka was then removed.
But Brother Turton did not tell the school community, other teachers, or parents that Brother Kostka was being investigated, that two other complaints had been made about him, or that he was removed due to the alleged abuse.
"Between 1962 and 1972, and 1983 and 1993, the relevant provincial of the Marist Brothers took no, or no adequate, steps to ensure that Brother Chute did not have contact with children through his work as a Marist Brother," the royal commission found.
"The church parties acknowledged that 'It is today a great source of regret to the Marist Brothers that Brother Chute's conduct was not reported to the police much earlier' so that later instances of abuse would not have occurred."
Similar failings were found in the case of Brother Sutton, who taught in NSW, Queensland, and the ACT from the early 1970s.
It took a string of complaints before he was finally removed from a school in Lismore in 1987.
Two years later, in 1989, the principal of a North Queensland school became aware that Brother Sutton had admitted to molesting a child who had committed suicide.
The principal told Brother Turton, the provincial, but neither told the police, and Brother Sutton was not disciplined.
Brother Sutton was later convicted of 67 child sex offences in relation to 15 students at schools in New South Wales.
Eight students from Marist College Canberra made civil claims after being abused, and were paid a total of $1.8 million.
The royal commission examined Marist as a case study, and held hearings mid-last year.