The head of the Principals' Federation says a convicted sex offender who used false documents to work in six North Island schools slipped through the cracks of an otherwise robust system.
Te Rito Henry Miki, 41, admitted using false CVs and a forged birth certificate to get teaching jobs.
He had evaded police and the Department of Corrections for several years and was able to use aliases and fake university degrees, one of which spelled the word bachelor incorrectly, to work with children.
Miki, sentenced on Friday to four years and six weeks in prison, had more than 60 previous convictions including common assault in New Zealand and Australia, and three of indecent assault on a boy aged 12 to 16 years.
The case has led a child abuse prevention agency to call for schools to investigate prospective employees more thoroughly.
Child Matters spokesperson Amanda Meynell says it is important for schools to do thorough background checks.
"Obviously if you had, at any point, any worries about someone's credibility or were worried that what they were presenting wasn't true, you need to look into that further."
Principals' Federation president Paul Drummond says while schools should not be complacent about how they deal with references and screening candidates for jobs, the systems are robust, and this was an exceptional circumstance.
But primary school teachers' union NZEI says the schools are not to blame for employing the man.
Union president Ian Leckie says criminals will always try and pick ways through the system.
He says in this case it does not necessarily mean the schools didn't do checks or did not get the assurances they needed.
A ministerial inquiry into how Miki was able to work at schools undetected is expected to be completed on 15 June.
Amanda Meynell hopes the inquiry will include some robust child protection policy recommendations.