The commissioner in charge of Rangiora High School says the decision to end principal Peggy Burrows' employment was "not made lightly".
Mrs Burrows spoke out yesterday after her gagging clause was lifted, saying she had been sacked and planned to challenge the decision.
Commissioner Bev Moore, who was appointed to the school in February last year after the ministry fired the board of trustees due to a relationship breakdown between it and the principal, said the nature of the employment relationship with Mrs Burrows was private and confidential. But she said advice from the School Trustees Association and legal advice had been taken to "ensure that a rigorous and fair process was followed".
"The process has taken some time to allow Mrs Burrows and her legal representative to consider the information and findings and respond throughout."
Last July TVNZ said Mrs Burrows was put on leave after accusations she breached a gagging order and leaked information to media.
Ms Moore said as part of her work at the school she had uncovered matters relating to integrity/security of documentation and a significant breach of privacy that needed to be probed by independent specialists.
Mrs Burrows said she was disappointed by the decision, which she said was based on unclear and unresolved allegations, and indicated she would be challenging it.
She said during her 13 years as head of the school she worked hard professionally and ethically despite more than a year of investigations. A public petition to reinstate her job received more than 1000 signatures.
Chen Palmer partner and employment lawyer James Dunne said there was a misconception that under the protective disclosures legislation a whistleblower was safe to pass information to media.
"One of the things that is tricky about our protective disclosures act is that it doesn't actually work that way," he said. "You have to go to an appropriate person first."
In regards to a school, he said appropriate authorities could include the Ministry of Education, NZQA, the Ombudsman or police, but very rarely would it be seen as appropriate to whistleblow to the wider public.
The stakes were even higher when it involved personal information of children, Mr Dunne said.
Meanwhile the Ministry of Education head of sector enablement and support, Katrina Casey, confirmed to the Herald the commissioner would remain at the school for a further year to continue to address the significant issues it faces.