"No victim would want to talk to him," Emma and Katie's father, Anthony Foster told reporter Tara Brown.

"Any victim who is sitting in front of a psychiatrist who also had that victim's perpetrator as a client would be horrified by that."

In a secret letter to O'Donnell’s lawyer, Mr Ball states he was fully versed with O'Donnell’s background and the nature of his offences.

However in a second letter written on the same day to the sentencing judge, Mr Ball directly contradicted his secret letter.

"I have had insufficient time to carry out a formal and detailed assessment," he wrote.

Mr Ball also failed to inform the judge that O'Donnell had admitted to offending recently. The sentencing transcripts confirm the judge relied upon this evidence when sentencing O'Donnell.

"It is of great significance in your favour that you have not offended against the law over those past eighteen years," the judge said.

O'Donnell could have faced 86 years in jail, but was instead sentenced to three years and nine months, only two of which were served.

He died in 1997 a free man.

Cardinal Pell's other main appointee on the "Melbourne Response" was Victorian QC Peter O'Callaghan, whose job was to assess if claims of abuse had taken place.

Like Mr Ball, Commissioner O'Callaghan was meant to be independent of the church, however evidence suggests they were instructed by and reported to the church’s longstanding law firm, represented by Richard Leder.

Correspondence between Mr Ball and Commissioner O'Collaghan suggests clear potential for conflict of interest, with Ball referring in one letter to victim Emma Foster as potentially costing "millions".

Peter Saunders, an abuse survivor appointed by the Pope to sit on Vatican's child abuse commission, has condemned the church's failure to protect and assist victims.

"The vilest crime on the planet is the assault, the rape of a child," he said.

"A very close second is to witness it and to do nothing."