The board had co-operated fully with the SFO, including providing the KPMG audit.
The trust, as part of its 2010 Treaty settlement, is receiving $1 million a year for 20 years through the Ministry for the Environment to care for the Waikato River. Four other Waikato and Waipā river iwi also receive the annual co-management payment.
Little is seeking advice on why such funds, even if they are part of a Treaty settlement, are not subject to any oversight.
But Little's counterpart David Parker, whose Environment Ministry distributes the payments, said checks and balances should be provided within the trust.
Berryman-Kamp said the board had offered to meet the ministers to discuss the issue and to show what had been achieved in the past eight years.
"Any minister is welcome to look at the Tarit board's reporting process, which includes the receipt of monthly financial accounts done by our highly respected external accountants and our annual audited accounts that are provided to our three beneficial iwi at annual general meetings.
"We also have an annual ministerial forum where we meet with the Prime Minister and ministers and last year received the five-year review of the river iwi treaty settlement instruments."
New Zealand Premium Whitebait, a company Tarit had invested in, went into receivership in April, prompting fresh concerns from elders.
Berryman-Kamp defended the investment, saying the trust's commercial arm was charged with growing the Treaty settlement so it could be self-funding by 2030.
"The whitebait company is one of our investments. Our co-shareholders include significant interests within and outside of Te Arawa. Our chairman was instrumental in bringing some of those people to the table."
The company, the country's only commercial whitebait farm, was recently sold by receivers to its creditor and shareholder, the commercial arm of Ngāti Tahu-Ngāti Whaoa, for $1.095 million.
Tarit represents the interests of the three Te Arawa River Iwi located within the Upper Waikato River catchment area - Ngāti Tahu-Ngāti Whaoa, Ngāti Kearoa-Ngāti Tuarā and Tuhourangi-Ngāti Wāhiao.