The commissioner embroiled in the latest scandal at the Royal Commission of Inquiry into Abuse in Care says he won't be stepping down.

Paul Gibson is responsible for the group of sexual abuse survivors who advise the Royal Commission as it investigates historical abuse of children in state and church care.

Yesterday it was revealed that a partner of one of the advisory group members is a convicted child sex offender and has attended gatherings alongside members of the group.

The minister responsible for the Royal Commission, Tracey Martin, has been taking legal advice and will meet commissioners today.

Tracey Martin said if she needed to take steps to ensure the success of the Royal Commission of Inquiry she would do so.

She was looking for a "logical reason" rather than a "lack of competence" for the three month time difference between being aware the man had convictions and finding out what they were.

"We've got a circumstance here that has alarmed the public, has alarmed survivors - and they're the most important people - and quite frankly it has alarmed members of Parliament," Ms Martin told Morning Report.

"While we appreciate that many survivors had lives that then, because of the trauma of their childhood meant that they gained criminal convictions later on in life, and we don't want to penalise them for that pathway by somehow stopping them being involved in the Royal Commission, there are certain crimes that are trigger crimes that strongly affect survivors.

"So I think with hindsight there are certain crimes that should have been screened for with anybody that was coming anywhere near the survivors inside the Royal Commission of Inquiry."

The final decision on whether Mr Gibson may have to resign rests with the Governor-General, but Ms Martin said she wanted the Royal Commission to succeed and keep the trust of survivors.

Photo: RNZ / Dom Thomas

"If that means that I need to take steps to ensure that if there is a lack of competence that something is done to ensure that that trust remains then I will take those steps."

If other members of panel expressed a lack of confidence a commissioner, it would be up to the Commission chairman to step in, she said.

In May, the inquiry's 20-member Survivor Advisory Group was set up to represent victims of abuse.

The commission knew at the time the partner of one of those members had previous convictions. The man often drove her to meetings and sometimes stayed to support her.

Mr Gibson said it wasn't until late last month that the man revealed in a meeting between the group's manager, the member and her partner what he had been convicted of.

"At the meeting with this Survivor Advisory Group member ... the due diligence process looked at asking questions of her partner who was in attendance.

"Through that process he disclosed the nature of his convictions and he said 'this is the first time anyone from the commission has asked about them' and he was, to some extent, relieved to share them."

Other members of the advisory group found out through the media.

Group member Kath Coster was horrified when she heard the news.

"Not the sort of thing I would have expected, being a state care survivor and being subjected to paedophiles through state care, to be involved on an advisory panel to help make changes, to find out that we've had a paedophile amongst us.

"To think that I put myself in a motel room with him, now knowing he's a paedophile, it's quite sickening."

Another member, Tyrone Marks, wants resignations.

"I'm talking senior management, chief executive level ... I think Paul Gibson should go as well."

Jane Stevens, who is also part of the group, backs that call.

"If our leadership can't get their act together, then they seriously need to look at whether we need a change of leadership."

Mr Gibson said he had no plans to step down from his role.

"I'm confident in the processes going forward. Yes, mistakes have been made and I acknowledge that."

Lawyer Sonja Cooper represents 1400 abuse complainants and said it needs to be made clear that victims who have convictions are not being excluded from appearing before the Royal Commission itself.

"We need to be very clear there is a distinction between the survivor panel meetings and the rights of people who are registering with the commission to tell their stories.

"What I'd be concerned about is the damage being done to the Royal Commission at this stage disenfranchises a very necessary voice in the Royal Commission."

National Party leader Simon Bridges told Morning Report the minister should have exercised more oversight earlier.

"This could have been prevented or stopped sooner had we had the basic vetting you'd expect," he said.

"Overall, can we have confidence in the commission? I think it's badly broken at the moment."

He said Mr Gibson's resignation may be required depending on what he did and what his processes around vetting were.

The Survivors' Advisory Group had been scheduled to meet today, but Mr Gibson said that was no longer happening.

All meetings have been put on hold until background checks on group members are completed, he said.