The Catholic Church says outside confession all offences against children must be reported to the authorities but the confessional seal cannot be broken.
An Australian pedophile priest, who was previously convicted for abusing dozens of children, believes clergy who learn about crimes in confession should report it to police.
Gerald Francis Ridsdale abused 53 children over three decades from the time he was ordained as a priest in 1961, although his true number of victims is believed to be in the hundreds.
The child abuse royal commission wants a new crime of failure to report child sex abuse in institutions, including when the information came from religious confessions.
But the Catholic Church believes the seal of confession must remain intact despite the prospect of its priests facing criminal charges for failing to report child sexual abuse.
Ridsdale's views on whether the confessional seal can be broken were raised during a pre-sentencing hearing on Tuesday, after the former Catholic priest pleaded guilty to abusing another 12 children.
During his evidence to the royal commission in May 2015, Ridsdale was asked if he believed if the confessor should tell the police if someone had confessed to a crime.
"Well, now from my experience and what I've done and the damage that I've done, I'd say yes, definitely yes," Ridsdale said.
"I don't know what the church ruling or legislation or thought is about that, but that's my personal opinion."
Ridsdale's defence counsel Tim Marsh said Ridsdale knew what he was doing was wrong.
"He accepted that he should never have been allowed to practise as a priest and he admitted the harm his offending caused," Mr Marsh told the Victorian County Court on Tuesday.
The Catholic Church's Truth Justice and Healing Council (TJHC) argues there should be an exemption from reporting requirements if information to child sexual abuse is revealed in the confessional.
"The TJHC respects the commission's processes but continues to maintain that the exemption remains in place," council CEO Francis Sullivan said.
Australian Catholic Bishops Conference president, Melbourne Archbishop Denis Hart, says confession is a fundamental part of the freedom of religion that must continue to be recognised by Australian law.
"Outside of this all offences against children must be reported to the authorities, and we are absolutely committed to doing so," he said.
The royal commission said the recognition of the right to freely practise one's religious beliefs must be balanced against the right of children to be protected from sexual abuse.