Concerns were first raised with the police 16 years ago about a teacher who this week admitted 49 charges of sexually abusing pupils of a school near Kaitaia in the Far North.
James Parker, 37, committed the offences against boys at Pamapuria School, where he was deputy principal.
Most of the 49 charges related to offences since 2009, and police believe there could be more victims.
But a former principal, who did not want to be named, told Radio New Zealand yesterday that she took her concerns about Parker to police when he was in his early 20s.
She said that back then, Parker was a first-year teacher and often had pupils stay at his house for "sleepovers".
The woman alleged he targeted a "poorer school" where parents were stressed and needed a break from their children. As a result, they were happy to let Parker have the youngsters at his home.
She also claimed that Parker abused Maori cultural traditions, like marae-style sleeping arrangements, to rationalise his letting pupils sleep in his bed - and even in his tent on school camps.
A complaint was made to police, however the principal said it was "never followed up properly", other than officers speaking to Parker in the school carpark.
Yesterday, it was also revealed that Parker was investigated by the police, Child, Youth and Family and the Ministry of Education in 2009. Following that, police wrote a "strongly worded" letter to the school's leaders, advising them that Parker should not be allowed to have any more pupils staying at his home.
Most of his offending occurred after that letter was sent.
Detective Inspector Karyn Malthus confirmed that the police were now investigating claims that "date back several years".
She would not be drawn on the specifics.
Ms Malthus confirmed that Parker and the pupils allegedly involved in earlier incidents were interviewed, but no charges were laid.
"Children were interviewed at the time and the matter could not be substantiated. Police reject any suggestion that we were responsible for any inaction. We took all steps possible within the law to make the appropriate notifications," she said.
"Police did interview Parker and notified the school of their remaining concerns. We could not sustain any allegations and were therefore limited in what we could do.
"When further evidence came to light recently, charges were laid and a thorough and professional investigation was undertaken."
Ms Malthus urged any victims who had not been to the police to come forward. Police also wanted to speak to anyone else with information about Parker's offending.
The board of Pamapuria School, just outside Kaitaia, quit when trustees learned of his sexual abuse. A commissioner is now overseeing the running of the school.
- Anna Leask, NZ Herald
