The royal commission has rejected Catholic Church concerns about the timing of hearings into sex abuse in an Adelaide special needs school.
Next month the commission will look into how authorities responded to the abuse at St Ann's school in the early 1990s.
Parents of the victims hope they will finally get answers about the paedophile bus driver who preyed on up to 30 children, most of whom could not speak.
Earlier this year, lawyers for the church's insurers wrote to the commission, arguing that hearings could influence compensation settlements.
"If the commission's investigation occurs before the hearing of the Civil Actions, the plaintiffs in the Civil Actions could have the benefit of seeing the School Entities' statements, documents and evidence, and being able to plan their litigation strategy accordingly," the church said in a letter.
"In this respect, the commission's investigation carries the risk that it could affect the litigation strategy adopted by the plaintiffs, the evidence filed, and the likelihood of settlement."
Senior church spokesman Francis Sullivan has denied the church was attempting to influence the timing of commission hearings.
"There was no instruction, there was no direction from anybody in the Catholic Church to do anything that would stop anything to do with the public hearing related to the Saint Ann’s case," he said.
"As a matter of fact, from the Archbishop down, we are very keen for all of that case to be publicly aired so that the royal commission can get the truth out."
On Friday in Sydney, the royal commission determined the sessions would go ahead as planned, but said the church's concerns had been noted.
Peter Humphries, the lawyer for families seeking damages, claims the church's letter to the commission is part of a pattern.
"It is actually consistent with what I was told [within] about three months of becoming involved with this whole process," he said.
"I started in May 2008 and by August of that year I’d been visited by two lawyers acting for the church who told me that their instructions were to take every legal point that they could."
Victims were all 'profoundly disabled'
Mr Humphries says the St Ann's case is "the most tragic example" of the sex abuse.
"The victims were all profoundly intellectually disabled. All but one without the power of speech," he said.
"So unable to communicate any of the distress that they felt and of course because of the fact that none of the abuse was disclosed, there was no treatment of it."
Peter Mitchell is one of the claimants seeking compensation for his son.
He has shown his son pictures of the man who was later found guilty of sexually abusing children and jailed.
"He pushed them away and said 'bad man, bad man'. That is the limit of his communications," Mr Mitchell said.
"So it was quite obvious he knew who that photograph was of and why he was calling him a bad man."
Father speaks of son's fear and paranoia
While Mr Mitchell's son struggles to speak, his father is under no illusion about the harm done at the school.
"He's by my side 24/7 when he's home with us. I have to sleep in his room when he comes home with us, because he is scared. He's paranoid," he said.
Mr Mitchell is now the driving force behind a petition, which began this week, calling on the church to settle the case.
It has gathered almost 80,000 signatures.
"The parents were going to the school in the '90s searching for reasons why their children's behaviour had deteriorated so badly and they were being told that nothing had happened there that could account for it," Mr Humphries said.
"And we now know it was the complete opposite to that."
Mr Sullivan stresses that the way forward is "not through the litigation system".
"I've got no idea about what’s going on in the particular matters, but can I be abundantly clear that the way forward for people who have been abused, sexually abused as children, is not through the litigation system," he said.
"We need an arrangement, like a compensation scheme that will focus on the needs of the individual, what they need now and what they need in the future to be properly supported, particularly when we are dealing with people who are disabled."
The Royal Commission into Institutional Responses to Child Sex Abuse will begin hearings in Adelaide on March 17.