It was a legal case that opened up one of the nation's most powerful institutions to a wave of damages claims from survivors of child sexual abuse.

But Judy Courtin's legal war with the Catholic Church began on a more personal level, with a devastating revelation from a nephew that he had been abused as a child by two Christian Brothers.

"He disclosed to me about the tragic, horrific crimes that were committed against him when he was 11 years of age," she said.

She was outraged he could not sue the Catholic Church for the crimes of its clergy, but a decade and a royal commission later, her small law firm took on another victim's case.

And she won that David and Goliath battle, getting the Catholic Church to admit that it was legally responsible for the crimes of notorious paedophile priest Gerald Ridsdale.

Ms Courtin's legal victory has paved the way for other abuse survivors to seek compensation from the Catholic Church. ( ABC News: Danielle Bonica )

But Ms Courtin is reluctant to take the credit.

She said it is her client, known as JCB, who was the true hero.

"It's taken a very brave, courageous client to not only come forward but to survive this really traumatising process," she said.

"We don't know at the beginning when we file what the outcome is going to be. It's a big risk. Our client takes huge emotional, psychological risks."

From advocates to legal warriors

Ms Courtin studied law late in life.

It was her nephew's appalling treatment by the justice system, and her PhD research on the treatment of sexual assault victims in the Catholic Church, that led her to set up her own legal practice two years ago.

Then she employed another long-time justice fighter, Chris Atmore.

Dr Atmore said she was someone who has "always wanted to act for the underdog".

Chris Atmore says the Catholic Church's legal tactics are at odds with its public statements of compassion for abuse survivors. ( ABC News: Dylan Anderson )

She had already been an advocate for domestic violence victims, including Rosie Batty, whose son was killed by his father at cricket practice in 2013.

But she had never taken on a litigation case in the Supreme Court.

The case, known as JCB's Against The Catholic Church, was her first.

Dr Atmore got the Catholic Church to admit to a court for the first time that it was legally accountable for Ridsdale's crimes against children.

The church admitted it was told in 1975 that Ridsdale was sexually abusing children and it did not stop him.

It was an admission the Catholic Church had already made to the Royal Commission into Institutional Responses to Child Sexual Abuse, but it doggedly refused for nearly two years to admit it to the Supreme Court.

Ridsdale abused JCB in 1982, and the church agreed in September to a multi-million-dollar compensation payout.

Dr Atmore is angry it took nearly two years to get the admission of liability from the church.

And while the outcome will make it easier for those abused by Ridsdale after 1975, it does not help those abused before that year.

"Despite the church's public expression of compassion for victims of clerical sexual abuse, no quarter is given when it comes to litigation," Dr Atmore said.

She said it may be well within the church's legal rights to have multiple hearings and draw out proceedings as they did with JCB.

"But I do question, in terms of the church's philosophy in teachings and their expressions of compassion, that perhaps they need to have a think on moral and ethical lines about is this the best way for them to instruct their legal team to operate in relation to victims of child sexual abuse," she said.

Gerald Ridsdale is believed to have abused hundreds of children over 40 years. ( Supplied )

The battle against time

Ms Courtin's phone is running hot as hundreds of victims come forward to make a claim.

She is worried many will die before their cases are settled.

"I've had three clients die in the last six months. I had one dear, dear man die only about a month ago," she said.

"I think four days before he died, he rang me at work, and he disclosed something for the very first time. He said he just can't cope anymore.

"Older people are dying too because of their age. They are all dying waiting for some form of justice."

She questions why institutions continued to fight the compensation claims.

"Why do they continue to try to crush victims and survivors?" she said.

"So many of our clients are getting elderly. They're unwell. They're psychiatrically unwell.

"A legal process is traumatic for anybody but for these people who are very vulnerable it's even more traumatic."

'Victims are still shunned'

Barrister David O'Brien acted for JCB and comes from a devout Catholic family.

He would also like the Catholic Church to show more compassion and admit liability for other victims of historical child sexual abuse.

"On behalf of the victims I represent, of course, and in the broader community and probably many Catholics in the Church, it would be helpful at this point," he says.

Mr O'Brien was also a member of Victoria's 2013 Parliamentary Inquiry into the Handling of Child Abuse by Religious and other Organisations when he was a state MP.

As a Catholic, he says he was disappointed in the Church's response to the parliamentary inquiry and the royal commission.

"The way they've treated victims — they haven't really embraced the victims community. Victims are still shunned," he says.

"The Church needs to take leadership and that leadership has to come from the top, to do things like admit liability earlier.

"They have the money in Rome. They've caused the liability and they need to pay for it as a very first step. That's penance. That's their teachings."

A spokesperson for the Catholic Church said its legal advice was to continue to consider each case individually.