Catholic Archbishop Christopher Prowse told the Royal Commission into Institutional Responses to Child Sexual Abuse on Tuesday there needed to be some "fine tuning" and "amendments" to the mandatory reporting laws taking force in the ACT from July.

As it stands, the scheme only covers clergy attached to a school or residential care organisations, Fairfax Media understands.

Child sexual assault campaigner Damian De Marco said the impression he had been given was that altar boys, religious camps and sporting groups would not be covered.

"It's a gap that's a worry considering what's coming out of the royal commission," Mr De Marco said.

It's also a gap that had already been identified in the NSW scheme by members of the clergy.

Archbishop Prowse told the royal commission he and his brother bishops in NSW had written to the NSW government asking them to include all religious bodies in its reportable conduct scheme.

But Mr De Marco told Fairfax Media this inclusion was yet to happen.

The archbishop was also grilled over his decision not to attend a Marist College healing ceremony last year.

"That was a mistake on my part," he said.

Counsel assisting the royal commission Gail Furness SC said the decision seemed at odds with his other comments during the hearing.

"I agree with you it was a mistake and I made a mistake for it and I'm sorry for it," Archbishop Prowse said.

He also hesitated when asked if he would raise the issue of secrecy within the church with the Pope.

"If I had the opportunity, most certainly. Certainly to the pope's representatives here in Australia, the nuncio. What that word secrecy means would need to be worked out at different levels," Archbishop Prowse said.

But the archbishop acknowledged the Catholic Church did not have the resources to deal with its "scourge" of abuse alone.

"The gravity of the sex abuse is really beginning to dawn on us. Even if we did [have the resources] it's not appropriate. The days of us in house looking at these on our own are gone," he said.

"With the government structures up now and the legislation which is very helpful it helps us to say I as an archbishop can't be making unilateral decisions about these matters without going to these other instrumentalities and working through it in that way.

"There's slightly different legislation in the ACT and we have been petitioning the ACT government to raise the bar on reportable conduct policies to be acquainted with NSW."

Archbishop Prowse said the church needed to be able to work more transparently with governments and not "think we are in a bubble or in another orbit".

However the ACT government maintained the scheme would adequately cover the clergy.

"The scheme certainly includes all religious institutions who provide these services to children in the ACT and importantly, will cover all ACT institutions whose employees were alleged to have committed abuse in evidence before the Royal Commission into Institutional Responses to Child Sexual Abuse," a spokesman said.

"It should be noted that the range of organisations subject to reportable conduct scheme oversight is still being considered by the royal commission. The royal commission has indicated its final report will contain recommendations relating to the need for nationally consistent schemes. This report is scheduled to be released in December 2017."

Cathy Kezelman of the Blue Knot Foundation said increasing accountabilities for clergy and lay people from religious organisations who are in positions of care for children was an important step in helping to establish and monitor child safety in organisations.

"Introducing a reportable conduct scheme would place the onus on each organisation to report any allegations or convictions to the central body and this should definitely include a mandatory reporting requirement for religious leaders," Dr Kezelman said.