MORE than 70 per cent of the Brothers from the St John of God order are suspected child abusers and the Catholic Archbishop of Sydney should immediately shut it down, says a psychologist who was employed by the order to meet scores of victims.

Michelle Mulvihill, who dealt with more than 120 of the order's child abuse victims during compensation negotiations, claims Cardinal George Pell was aware of a loan by the Catholic Church to the order, which was later used by the order to pay victims of abuse.

Denied involvement in any investigation of abuse within the order ... Cardinal George Pell. Credit:James Alcock

She also alleges the order has never properly supervised suspected paedophile Brothers and has hid documents relating to the abuse in places where police ''would never find them''.

Dr Mulvihill's revelation came as the former prime minister Malcolm Fraser joined the independent MP Tony Windsor and the senator Nick Xenophon in calling for a national royal commission into sexual abuse by religious groups and other institutions, after claims by Detective Chief Inspector Peter Fox last week that the church was still covering up the crime.