Liberal Leader Jeremy Hanson said Ms Burch had many questions to answer, "in particular how a convicted criminal was allowed into schools to interact with schoolchildren without a Working with Vulnerable People clearance".

"The safety of our children must be the priority and, in this case, for reasons unexplained, the law has been broken," he said. "The question is whether this is a systemic problem and other criminals are regularly exposed to schoolchildren, or whether this particular individual received special treatment."

Ms Burch was absent from the chamber for much of the morning and a motion she was to bring to set up an inquiry on gaming machines was put off for the day. But she appeared at Question Time, when she was asked by the Opposition whether she had given any directions or guidance to her directorate to facilitate visits by her son to schools, to which she answered "no".

Lloyd Burch was convicted of aggravated robbery in April and given six months to turn his life around before sentencing, during which time he was taken on by Menslink in its Silence is Deadly program, visiting schools to talk to teenage boys. His volunteer work and a reference from Menslink chief executive Martin Fisk helped him escape a jail term when he was sentenced in June.

Mrs Burch has not answered media questions on whether she spoke with youth mentoring group Menslink about helping her son, beyond saying it was his responsibility, and had no bearing on her ministerial responsibilities. Ms Burch is Minister for Education, and was Minister for Multicultural Affairs during last year's festival.

The issue has left many at Menslink unhappy, including the board, whose then chairman Peter Clarke said he had been "absolutely aghast" at the discovery of Lloyd Burch's criminal conviction. Menslink says Lloyd Burch shouldn't have been in schools with that background and did not have the required Working with Vulnerable People card – a breach that Menslink self-reported to the Office of Regulatory Services, which imposed a $2500 fine on the group.

Staff are unhappy they were expected to take Lloyd Burch into schools without knowing about his background, although they were told he was the education minister's son.

But a spokesman for Chief Minister Andrew Barr said it was an "administrative oversight" and the matter was closed. "It is unfortunate for Menslink that there was an administrative oversight in this case, but this should not detract from the excellent work they do with young men in our community," he said, dismissing the concern as "media hysteria".

He was not briefed about "the private lives of his colleagues' adult children" and had found out "at roughly the same time as the rest of the community", he said, echoing Ms Burch's insistence that it had "no bearing on her ministerial responsibilities".

Menslink's main funding is through the Community Services directorate (Mr Barr's portfolio last year), but the Silence is Deadly program received some funding from the Education Directorate.

On Thursday, education groups expressed concern and restated their support for laws that require regular visitors to a school to have a Working with Vulnerable People card.

Australian Education Union ACT branch secretary Glenn Fowler said, "Yes, we are concerned that there appears to have been an omission."

"We expect that legislation to be complied with. We are concerned about any situation in which someone is on school grounds when that visit does not comply with the legislation."

It is unclear what Lloyd Burch talked to students about. Menslink staff say his conviction for aggravated robbery was not the kind of information shared with school students, but Menslink chief executive Martin Fisk provided a reference for him for his October sentencing in which he said Lloyd Burch had been speaking since April "about his spiral into drugs and the crime he committed".

A strong supporter of the Silence is Deadly program, the principal of Stromlo High School, Dr Michael Kindler, said It would be "absolutely not" appropriate to have young men speaking about their crimes or drug use. He pointed to a different group including reformed drug addicts that made school visits, which Dr Kindler said he did not allow in his school because it "scandalises and dramatises personal experience".

"I strongly discourage such practice because it is counter-productive," he said. "Educating young people is not achieved through fear of them ending up in such situations. Educating young people to deal with emotional matters such as instability, self-harm, anxiety, depression is best addressed by people who are properly qualified."

Stromlo High School was one of many schools to host a Menslink visit last year, but Lloyd Burch was not among the visitors. Dr Kindler said all of the Menslink team had signed in and showed their Working with Vulnerable People documentation.

The team had talked about the need to speak up and get help, about friendship and darker issues such as depression, self harm and anxiety. He had been impressed with their ability to involve large groups of boys in discussion and it would be a shame if the current controversy cast a cloud over that, he said.

The schools visited by Lloyd Burch have not been divulged.

Belconnen High School principal David McCarthy said he strongly supported the Silence is Deadly program, which was well run and saw an increase after each visit in the number of boys seeking help and counselling. Lloyd Burch had not visited with Menslink and the school had a very clear policy of checking Working with Vulnerable People cards, he said.

The director of Catholic Education, Moira Najdecki, said the organisation ensured volunteers obtained the cards in line with the law. The assistant secretary of the Independent Education Union's ACT branch, Carol Matthews, said the law was providing important protection for schoolchildren, a message echoed by the the ACT Council of Parents and Citizens Associations.

Also on Thursday it emerged that Mr Fisk provided a second reference for Lloyd Burch, for his April court case. In that reference, Mr Fisk said Lloyd Burch had collected money twice for Menslink – at the Multicultural Festival in February and at a Brumbies match in March.

"I was personally very impressed when he volunteered for us again in March, as I understood this was on his own initiative and not on the recommendation of his family," Mr Fisk wrote.