The Waitangi Tribunal has found the Crown breached its Treaty duty by failing to ensure Māori claimants had adequate funding to participate in the Tribunal process.
Claimants had argued a lack of funding compromised their ability to make and pursue their claims, which undermines the institution as a pillar of New Zealand's constitution.
Claimants have been seeking a solution for several years, including through an urgent inquiry. Public hearings were held at the end of last year.
The Crown conceded there were problems with current funding arrangements, but argued they were good enough in Treaty terms.
The Tribunal did not accept this, adding it was particularly concerned that officials knew about the inadequacies, but government ministers did not act on their advice.
In a letter to ministers, presiding officer Judge Carrie Wainwright said "the Crown has acted too slowly and ineffectively to implement a comprehensive system, even though the ad hoc arrangements were widely recognised as deficient."
Thr Tribunal said it was part of the Crown's duties to ensure a smooth and culturally appropriate process, adding that it was urgent the Crown and Māori come together to find an adequate solution.
"A comprehensive system must be designed that funds claimants to bring and run their claims effectively, so that they can compete fairly against the resources of the Crown," Wainwright said.
The Tribunal said it was not acceptable in an area of policy that primarily affected Māori for the Crown to come up with policy and leave "consulting" Māori to the end.
It also recommended a standardised funding protocol until long-term arrangements could be agreed on.
The report is part of a wider inquiry into Māori experiences with the justice system.