The Catholic Church wants the truth exposed at the royal commission into responses to child sex abuse, and will pay compensation to victims, its representative says.
Truth Justice and Healing Council chief executive Francis Sullivan says the commission will be embarrassing for the church but it is imperative the truth emerges.
''We are going to encourage, wherever possible, individuals to come forward with their experiences so that the truth can come out,'' he said.
''The church leadership in Australia have made it clear that they are going to be open and honest and cooperate fully.''
Sullivan said the church would pay compensation where appropriate.
''We are dead keen on making sure that compensation, and appropriate compensation, is put in place,'' he said.
Sullivan said any existing confidentiality agreements would be cancelled so victims could tell their stories.
Victims' advocacy group Broken Rites spokesman Wayne Chamley said he took Sullivan at his word, although he hoped senior Catholics would not interfere in the process.
''The question is how strong are his delegations, or is some cardinal or some bishop, or a group of bishops, going to come in at some point and override him and say no, this is the way we're doing it,'' he said.
''Part of what has gone on has been influence from outside of Australia.
''If we start to see the church taking out injunctions and pulling this and holding that, which will have the effect of delay, delay, delay, then the leopard hasn't changed its spots.''
The Truth Justice and Healing Council will represent the Catholic Church at the commission into institutional responses to child sexual abuse, which held its introductory hearing in Melbourne on Wednesday.
Adults Surviving Child Abuse president Dr Cathy Kezelman said the commission was off to a positive start but she was concerned about the level of training among support staff.
She said it was crucial that support workers had adequate training, to prevent victims from being retraumatised.
''They're being confronted with tales of extreme horror day in and day out, so their wellbeing and health is absolutely critical,'' Dr Kezelman said.
Counsel assisting the commission, Gail Furness SC, said extensive steps would be taken to reduce the stress victims might experience by giving evidence, including having trained counsellors available.
Leonie Sheedy of the Care Leavers of Australia Network, an organisation for people who grew up in children's homes or foster care, said some victims had been waiting years for a royal commission.
''It's a very momentous occasion today,'' she told reporters.
''I call this Australia's grubbiest little secret. We've been invisible to our society and to politicians.''