The way a Victorian bishop dealt with pedophile priest Gerald Francis Ridsdale was a catastrophe for both victims and the church, Cardinal George Pell says.

Former Ballarat Bishop Ronald Mulkearns knew in 1975 Ridsdale had abused boys, but moved him between parishes and did not suspend his priestly faculties until 13 years later.

"The way he was dealt with that was a catastrophe, a catastrophe for the victims and a catastrophe for the church," Cardinal Pell told the child abuse royal commission from Rome.

"If effective action had been taken earlier an enormous amount of suffering would have been avoided.

"He simply gave him chance after chance after chance, shifted him around and initially at least trusted excessively in the possible benefits of psychological help."

The first time Ridsdale was being treated for anxiety caused by the possibility of being charged by police, the inquiry has heard.

Cardinal Pell said he was not aware of priests being sent for treatment for sexual offending in the 1970s and early 1980s by Bishop Mulkearns.

Cardinal Pell was a Ballarat priest and one of the advisers to Bishop Mulkearns, the 1971-1997 Ballarat bishop.

He said he did not know of anyone else in the church hierarchy who knew about Ridsdale's offending at the time.

"I did not know that Mulkearns knew let alone anybody else."

The commission has heard Mulkearns destroyed documents from Ridsdale's file relating to his treatment, which Cardinal Pell said was unacceptable.

Ridsdale has been jailed for abusing 53 children but is the subject of 78 abuse claims to the diocese.

It is believed Ridsdale abused at least 1000 children across the western districts of Victoria, victims' advocacy group Broken Rites has said.