A forensic audit is under way into spending and investments made by Te Arawa River Iwi Trust.
The trust is charged with restoring the health of the Waikato River. It is set to receive millions of dollars of taxpayer funding over the next 20 years.
Earlier this year, RNZ News obtained a letter sent by Sir Toby Curtis and six other Te Arawa leaders to Crown ministers.
It raised concerns about the way the trust was being run and a potential conflict of interest with the trust and its chairman Roger Pikia's personal business dealings.
Withdrawals from the trust's bank account in January this year suggested its investment arm, Tarit Ltd, had invested $775,000 in Ka Ora Limited. The Companies Office shows Tarit Ltd has a 45 percent shareholding.
Mr Pikia is a director of Ka Ora Limited, and has a 13 percent shareholding through another company, Aotearoa Inc Limited.
At that time, Mr Pikia said that any conflicts of interest had been declared.
The trust's acting chief executive, Eugene Berryman-Kamp, said the the audit should be completed before Christmas.
Mr Berryman-Kamp said once the board had the final audit findings, it would consider whether further action was needed.