The board was reviewing the school's entire policy framework.
The letter said allegations had been made about current board members misappropriating school resources. That was rebuffed by Mr Dephoff, who said "in no way" had board members misused their positions or school resources. Auditors and and the board's new monitoring systems would safeguard the school from any such risks in the future, he added.
Katrina Casey, the Ministry of Education's head of sector enablement and support, said a review of the school's financial position was part of the ongoing investigation.
In the meantime, the board of trustees was performing strongly and ensuring teaching and learning continued smoothly at the school.
"We are confident the board has all the right skills to steer the school through this transition. The board will be advertising for a new principal in the near future," she said.
The ministry would not comment on whether it would seek financial redress or lay a complaint with police, saying it would wait for the outcome of the financial investigation.
Kawakawa Primary is a decile-one, Years 1-8 primary school. Its roll is 90 per cent Maori.
Mr Dephoff was busy yesterday in his day job as a Kawakawa police officer and could not be contacted for further comment.