The extent of alleged paedophilia in Catholic institutions has been laid bare for the first time with a royal commission hearing that almost 4500 people have made claims of child sexual abuse over the past 35 years.
Data gathered by the Royal Commission into Institutional Responses to Child Sexual Abuse show some Catholic orders including St John of God, Christian Brothers and the Marist Brothers had a high proportion of alleged perpetrators.
Francis Sullivan, chief executive of the Truth, Justice and Healing Council, which assisted the royal commission's analysis of alleged abuse, became emotional as he addressed the public hearing before Justice Peter McClellan.
"These numbers are shocking," he said.
"They are tragic and they are indefensible. Each entry in this data ... represents a child who suffered at the hands of someone who should have cared for and protected them. As Catholics, we hang our heads in shame."
The royal commission will spend the next three weeks re-examining the Catholic Church's response to alleged child sexual abuse.
The commission heard that more than a third of people who gave evidence in private sessions over the past four years reported abuse in Catholic institutions.
Fifteen public hearings have been conducted into Catholic Church authorities since the commission started in 2013 and almost 390,000 documents have been produced to the commission in that time.
Counsel assisting the royal commission Gail Furness, SC, described the testimony of survivors as "harrowing".
"The accounts were depressingly familiar," she said.
"Children were ignored or worse, punished. Allegations were not investigated. Priests ... were moved. The parishes and communities to which they moved knew nothing of their past. Documents were not kept or they were destroyed. Secrecy prevailed as did cover-ups.
"Many children suffered and continue as adults to suffer from their experiences in some Catholic institutions."
The royal commission has made 309 referrals to police in all states and the ACT in relation to allegations of child sexual abuse involving Catholic Church institutions, with 27 prosecutions resulting.
The commission, assisted by the Truth, Justice and Healing Council, conducted a survey into Australian Catholic institutions.
Ms Furness told the hearing 1880 alleged perpetrators were identified in claims of child sexual abuse. Of the 1880, 32 per cent were religious brothers, 30 per cent were priests, 29 per cent were lay people and 5 per cent were sisters.
The research examined 75 Catholic authorities over a 60-year period between 1950 and 2010, the commission heard.
The dioceses of Lismore, Wollongong, Port Pirie, Sandhurst and Sale had the highest proportion of allegations of abuse.
Of religious orders with only religious brother members, the highest proportion of alleged perpetrators were members of St John of God (40.4 per cent), the Christian Brothers (22 per cent), the Salesians of Don Bosco (21.9 per cent), Marist Brothers (20.4 per cent) and the De La Salle Brothers (13.4 per cent).
Some of Australia's most senior Catholics will give evidence at the inquiry, including the Archbishop of Sydney Anthony Fisher, the Archbishop of Melbourne Denis Hart, the Archbishop of Brisbane Mark Coleridge, and the Archbishop of Adelaide Philip Wilson, who has been charged with concealing child abuse.
The hearing continues.