A Victorian inquiry into child sexual abuse has heard the former Bishop of Ballarat made a terrible mistake by allowing a known paedophile priest to continue working.

Father Gerald Ridsdale was convicted and jailed for child sexual abuse in 1993 and again in 2006.

The Victorian Parliamentary Inquiry into Child Abuse has been told that by 1975 representatives of the Catholic Archdiocese of Ballarat, in western Victoria, had solid evidence of his crimes but he was not removed from his duties and was instead moved onto other parishes.

The inquiry heard that the bishop in charge of the Ballarat diocese during the time that Ridsdale worked there, Bishop Ronald Mulkearns, was not fit to front the inquiry because he had suffered a stroke and now had poor memory.

The bishops that served after Father Mulkearns' retirement gave evidence in his place.

Bishop Paul Bird told the inquiry that Father Mulkearns received bad advice on how to manage Ridsdale and had made a terrible mistake in allowing him to continue serving in various parishes.

"It wasn't wilful blindness. It was a tragic mistake on his part," Father Bird said.

"It was, he believed, the accepted opinion at the time that dismissal was not the first option, but that a person might be referred for treatment in the hope that they would correct their behaviour.

"It proved to be a terrible mistake and I accept that fully.

"Looking back, Gerald Ridsdale should have been taken out of the ministry when there was a first report of offences."

The inquiry heard there was evidence of Ridsdale's offending from at least 1975, and that there was a police investigation of a complaint from the Inglewood parish.

But other than to move Ridsdale around, including time out in Melbourne, Sydney and the United States, he was not removed from duties and continued to offend.

Under questioning from inquiry committee member Frank McGuire, Father Bird told the committee that more than 100 cases of abuse were substantiated in the Ballarat Diocese and 67 of them were by Ridsdale.

"Around 94 per cent of the claims were accepted as substantiated," Father Bird said.

'Devastating harm'

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Earlier, the Salesian Order gave evidence at the inquiry that the order had paid out more than $2 million in compensation to victims of child sexual abuse and that the order had 49 complaints against its priests in Victoria.

Father Greg Chambers told the inquiry there may have been communication between paedophile priests in the order.

"I've always believed that there was no collusion or communication between abusers within our province," he said.

"But I've got to admit that as I've been following certain current cases that have come to court and reading the testimony of various people, I've come to an awareness that there has been, or could be, some possible communication between certain individuals."

Some of the evidence from the Salesian Order was held in camera as three priests are due to face court later this year relating to abuse allegations.

During evidence from the St John of God brothers, the inquiry heard there were 31 cases of abuse involving 15 brothers, and that at the time there were no more than 60 brothers in Victoria.

Representatives of the order told the inquiry it had not conducted any investigation into the apparent culture of paedophilia but was open to doing so.

They said the focus had been on dealing compassionately with victims of abuse that had been coming forward since the early 1990s.

Evidence from the St John of God brothers ended with a statement of apology read by the head of the Australian order, Brother Timothy Graham.

"We shamefully acknowledge the great harm that has been perpetrated by some of our members," he said.

"All of our brothers daily live the shame of the devastating harm that has been wreaked by some of their number in the lives of vulnerable people in our care.

"Beyond acknowledgement of the harm, the brothers of Son John of God humbly ask the forgiveness of our victims if they are able to give it.

"And we ask forgiveness of their families and friends, and we humbly ask the forgiveness of the members of the church and the people of Victoria."