Bishop Carroll, who held the See from 1983 to 2006, said the actions of a relatively small number of people had also damaged the church and seriously undermined the morale of many other members of the clergy.

"I can personally attest that many good clergy are horrified by what has occurred," he said.

Bishop Carroll, who now lives in Wagga Wagga, but maintains close ties with his former diocese, has welcomed Prime Minister Julia Gillard's announcement of a royal commission into sex abuse - as long as it is thorough.

"It [the royal commission] is a good thing," he said. "It is good the whole, awful thing be looked at."

Asked if the community's desire for retribution ignored the fact many abusers had been victims themselves, Bishop Carroll said: "Two wrongs don't make a right. I appreciate the point you are making but we have to keep the principal object in view."

Bishop Pat Power, who retired as Auxiliary Bishop for the diocese in June, has previously described sex abuse by clergy as one of the "most vexing issues" facing the Catholic church, could not be reached for comment on the royal commission announcement.

Australia's most senior Catholic says the royal commission will help determine whether reports about child abuse in the church have been a "significant exaggeration".

"We think it's an opportunity to help the victims. It's an opportunity to clear the air, to separate fact from fiction," Cardinal George Pell said in Sydney.

The Australian Catholic Bishop's Conference has said, in a statement, that child sex abuse "is a serious issue not just for the Catholic Church, but for the whole community".

"As Catholic bishops and individuals we share the feelings of horror and outrage which all decent people feel when they read the reports of sexual abuse and allegations of cover ups ... a royal commission will enable an examination of the issues associated with child abuse nationally, and identify measures for better preventing and responding to child abuse in our society."