One of Australia's most senior Catholic priests said his role was to deal with sexual abuse cases only after they had been made public.

Archbishop Mark Coleridge said it would not be appropriate to quiz the clergy on their sex lives when asked how the church's structure allowed more than 4,000 Australian children to be allegedly abused.

Speaking at the Royal Commission into Child Sex Abuse on Wednesday, Father Coleridge described the relationship between a priest and bishop as "delicate".

He argued that as his role was in the Church's "external forum", he had no right to question priests about their sex lives.

"How could I justifiably inquire of a priest what his sexual behaviour was when it hadn't emerged into the public forum and become a problem in the community which he was supposed to lead?"

"How could I justifiably inquire of a priest what his sexual behaviour was when it hadn't emerged into the public forum and become a problem in the community which he was supposed to lead?"

"I have no right to go to a priest who is not an employee of mine and say 'excuse me, are you in a sexual relationship?' At that point I would be intruding into what is called the internal forum.

"The priest would have every right to say it's no business of yours."

Many sex abuse survivors at the inquiry were visibly upset by the statement.

Father Coleridge remained adamant his responsibility was to deal with the issue once it came to light and said he had on several occasions.

The Royal Commission has heard of 4,444 cases of people allegedly being abused between 1980 and 2015 in around 1000 different Catholic institutions.

He said a counsellor, spiritual advisor or confessor were in better positions to ask those questions and determine if the priest was "not functioning effectively".

"That is something that would pertain to someone providing professional supervision or spiritual direction rather than something that would pertain to the bishop."

The Brisbane-based archbishop said there were various accountabilities "built into clerical life".

But he conceded it was "not enough" to stop priests preying on young members of the church.

Father Coleridge disagreed when asked if he thought the structures that stopped bishops from making these inquiries were "flawed".

"I cannot possess my own clergy," he said. "There are certain things I am not entitled to know."

"I am trying to imagine how that would work out practically. How I would discover the details of a priest's sexual life?" he added.