A number of government agencies are potentially in the gun following revelations a convicted sex offender worked on and off at schools for 12 years.
Ministers were informed late last week that the convicted offender had been arrested while allegedly in breach of their conditions of release.
It's been revealed the offender, who is now in custody, has worked at up to eight schools but court suppression orders mean Education Minister Hekia Parata can't confirm which schools may have been involved, or even if the offender is male or female.
A ministerial inquiry has been launched to look at how the person fooled the system.
Prime Minister John Key says the system needs a shake up because it's absolutely critical the confidence of parents is restored.
"We just need to understand why this person seems to have slipped through the cracks, we know that they are a fairly devious person obviously but we just don't know exactly why the system has failed to pick them up," he says.
"The only way we will restore confidence when, in my view, there's a full Ministerial Inquiry where we frankly rip the system apart and find out what went wrong and why."
Two schools and the parents of children at them have already been told the person worked there.
Derek, whose daughter goes to one of the schools in question, received a letter last night informing him of the situation.
"I've got a 16-year-old daughter and I've got a 15-year-old daughter and I've also got three sons so it's really close to home," he told Newstalk ZB's Danny Watson.
"It was just a big shell shock last night and then for it to come out in the news, I thought just as a concerned parent, someone should know that it's actually local and it's happening and we need to be aware of it."
Education Minister Hekia Parata has announced a ministerial inquiry into the matter conducted by former ombudsman Mel Smith which will look at how the individual was able to exploit opportunities in the system and how it can be prevented from happening again.
"At this stage, I cannot discuss the details of this individual case as the matter is now before the courts and therefore there is very little information that can be made publicly available at this point. However, I am extremely concerned by the details of this case," says Ms Parata.
"Parents should be able to send their children to school confident that an individual of this type is not part of the school environment."
"Clearly there are weaknesses in the system and that is why I have taken this very serious step of establishing a ministerial inquiry and asking someone of the seniority of Mel Smith to begin and begin immediately," Ms Parata says.
The offender was convicted of a sexual offence involving a minor in 2004.
They're understood to have worked irregularly in the education sector since 2000.
Ms Parata indicates the person has been employed at up to eight schools before being found out.
"The schools that were immediately affected have been notified. School communities have been informed and the Ministry of Education is actively working with those schools. It is possible that several other schools have also been affected," says Ms Parata.
“We have asked the courts to vary suppression orders so that we can work with other schools that may have been affected and they can inform parents.''
"On the face of it it would appear that that was the case. This case is somewhat exceptional in that it appears that multiple identities have been used."
Labour is supporting the move, with MP Nanaia Mahuta saying it's imperative children are taught by people of good character.
New Zealand First is also on board, but MP Tracey Martin says the vetting system used for teachers' credentials needs checking as well.
Ms Parata has asked for the inquiry to report back no later than April 30, 2012.