For centuries, the sacrament of reconciliation - known as confession - has been a venerated practice of the Catholic Church, requiring people to reveal their sins to a priest, who must keep the confession secret.
But the seal, or secrecy, of the confessional is under threat in Australia, following an inquiry which recommended that priests be forced to tell police about admissions of sexual abuse of children.
So far, South Australia, Tasmania and the Australian Capital Territory have adopted the proposal into law. Other states are expected to follow.
But the move has prompted a fierce backlash from the Catholic Church, with some priests warning that they would rather go to jail than break the confessional seal.
The recommendation was made by a five-year Royal Commission into child sexual abuse, which heard horrific cases of abuse in the Catholic Church and other institutions across Australia dating back decades. The commission concluded that the practice of confession had "contributed to both the occurrence of child sexual abuse in the Catholic Church and to inadequate institutional responses to abuse".
"(Confession) enabled perpetrators to resolve their sense of guilt without fear of being reported," it said in its final report last December.
Responding to the report earlier this month, Australian Prime Minister Malcolm Turnbull declared that the safety of children should take priority over the secrecy of confession. But he said the Federal Government will need to work with the states to develop a national response because the issue is subject to state and territory criminal law.
"The safety of children should always be put first," he said.
"We know, thanks to the Royal Commissioners' work, that in far, far too many cases, it wasn't."
On Wednesday, Tasmania became the third Australian jurisdiction to "lift the veil on the confessional" and announce laws to prosecute priests who fail to report child sexual abuse.
"I realise that that has implications for centuries-old canon law," said Tasmania's Attorney-General, Ms Elise Archer. "But we must remember that the recommendations are… to ensure that not only the survivors of child sexual abuse receive the care and attention that they deserve, but (they) also will prevent this abuse from happening."
Other states are planning to introduce similar laws.
But the Church in Australia has strongly resisted the change, saying there is no evidence it will reduce crime and that many priests would in any case advise criminals to confess to police.
Catholicism is one of the world's biggest religions, with about 1.2 billion followers. In Australia, 23 per cent of people are Catholic, making it the country's largest religion.
"Removing priest-penitent privilege from the law and requiring mandatory reporting of confessions will either have no effect on child safety or will actually make children less safe," Australia's Catholic Bishops said in a letter to Mr Turnbull.
Church officials said criminals will not confess if they know they will be reported to the police and so priests will not be able to urge them to turn themselves in.
A priest in Sydney, Father Michael Whelan, said he was willing to go to jail rather than break the confessional seal. "The state will be requiring us as Catholic priests to commit what we regard as the most serious crime," he told ABC News.
"I'm not willing to do that… When state tries to intervene on our religious freedom… we will resist."
But victim groups and survivors of child sex abuse urged the states to make the change.
"Children are the most sacred thing we should be putting first, and well above any rule about the confessional," Ms Helen Last, who runs an organisation that supports survivors, told The Sunday Herald Sun.
An expert on religion in Australia, Deakin University associate professor Andrew Singleton, said most of Australia's Catholics were not highly observant and would support the broader community view in favour of removing the seal in child sex assault cases. Most would "not go to confession often, if at all", he said.
"Attending confession has been greatly diminished in recent years," Dr Singleton told The Sunday Times.
He said he believed Catholic leaders should consider the commission's recommendation and consult the Vatican on the possibility of changing the Catholic practice.
Asked about priests willing to go to jail rather than breaking the seal, he said: "If a priest might regard himself as a martyr, he has lost touch of the bigger moral picture. The community sentiment is that (retaining the seal for child sex assault) is misguided."