The organisation that administers the Waitangi Treaty Grounds says the Serious Fraud Office is looking into "financial irregularities".
Dennis McBrearty, acting chairman of the Waitangi National Trust Board, says a probe was launched "as soon as the irregularity was discovered".
McBrearty told the Herald the irregularities related to transactions over a 12 month period beginning in 2016, and had been picked up by staff during routine analysis of accounts.
The Serious Fraud Office is tasked with investigating and prosecuting serious financial crime, typically frauds exceeding $5 million or with significant public interest.
McBrearty confirmed the irregularities fell below the $5m threshold, but said "specialist advice" sought by the board had recommended a SFO referral given the "public nature" of the trust board.
McBrearty said the irregularities were not significant enough to threaten the solvency or future of the Trust.
"I don't believe it'll place the Trust at risk. Obviously if there were funds missing we have banked on previously, it will leave a hole – but certainly the Trust is in a satisfactory financial position," he said.
According to the most recent financial statements filed to the Charities Register, for the year to June 2016, the Trust earned revenue of $11.5m during the period - including $5.6m in government grants - and had $28.5m in net assets, largely land and buildings..
The SFO had been informed of the matter in late December, McBrearty said.
In a written statement the SFO confirmed the referral and said "We are making enquiries. We will not be making any further comment at this time."
McBrearty also declined to provide further details: "The matter is now with the SFO and we will await the findings of their official enquiry. We are unable to comment any further pending the outcome of the SFO enquiry."
UPDATE: An earlier version of this story incorrectly included a picture of an event held by the Atea a Rangi Educational Trust at the Waitangi Regional Park in Napier. The region and organisation are unrelated to the Waitangi National Trust Board. The error is regretted.