A Victorian bishop's evidence about what the Catholic Church knew about pedophile priests could be a "game changer" although some fear he may take his secrets to his grave.
Former Ballarat Bishop Ronald Mulkearns, who has only months to live, will give his long-awaited evidence to the child sex abuse royal commission this week but it could be a futile exercise.
Bishop Mulkearns has told his doctor his memory of relevant events is vague and the commission has been warned his cognitive impairments mean he may not be able to effectively answer questions.
Ballarat abuse survivor Stephen Woods does not hold much hope that Bishop Mulkearns will reveal all.
"His whole life has been about covering up. Why would he start being honest now," Mr Woods said.
"He's about to die. He's going to go to the grave, he's going to go to hell, with his secrets."
But others hope Bishop Mulkearns will tell the truth after previously avoiding giving evidence to the commission and a Victorian parliamentary inquiry on health grounds.
"Our fingers are crossed in hope," said David Ridsdale, a nephew and victim of Australia's worst pedophile priest Gerald Francis Ridsdale.
"There's a huge difference between truth and proof, I've discovered. I really hope that Bishop Mulkearns chooses to tell the truth."
The commission has evidence the 1971-1997 Ballarat bishop knew Ridsdale and others were sexually abusing children and moved them between parishes, and he also destroyed documents in Ridsdale's file.
Bishop Mulkearns has advanced colon cancer and victims' advocacy group Broken Rites spokesman Wayne Chamley says he has nothing to lose by being honest about how much he did know and whether he shared that knowledge.
That could have implications for Cardinal George Pell, who as a Ballarat priest was an adviser to the bishop, Dr Chamley said.
"It's possible that the evidence given by Mulkearns might be the game changer," Dr Chamley said.
"He (Cardinal Pell) may have to answer some things that he otherwise wasn't expecting to answer."
Mulkearns is central, depending on what way his evidence goes, Dr Chamley said.
"He might just say he can't remember, he can't remember, he can't remember."
Bishop Mulkearns' evidence, which may be via videolink from his Ballarat nursing home, will precede Cardinal Pell's third commission appearance from Rome from February 29.
The commission could bring documents to light that could help establish negligence against church authorities, said lawyer Vivian Waller, who acts for nine survivor witnesses in the hearings and 35 Ridsdale victims pursuing negligence claims against the diocese.
"The hearings are also an important symbolic process for victims/survivors for whom it is vitally important that persons in key positions of authority are called to account for what occurred on their watch and under their noses," Dr Waller said.
"Victims/survivors have waited a long time to hear from former Bishop Mulkearns and George Pell about their involvement in the Diocese of Ballarat, a parish with an unfortunate and intense cluster of clergy sexual abuse occurring over a long period of time."
