Law Professor Jane Kelsey of Auckland University says iwi have mis-understood how much involvement they are likely to have in the running of any future privately-run prisons.
Parliament's Law and Order Select Committee is considering a bill allowing prisons to be managed privately.
With Maori comprising a significant proportion of prisoners, Corrections Minister Judith Collins says iwi involvement is crucial.
However, Professor Kelsey says there's no obligation in the Corrections Amendment Bill for those tendering for future prison contracts to take iwi participation into account.
She says there's no requirement for future private management operators to include any criteria or programmes specifically designed to meet the needs of Maori.