Green Party co-leader Metiria Turei is accusing iwi groups of naivete in their support for private management of prisons.
Waatea News reports iwi including Tainui, Ngati Whatua and Nga Puhi have investigated possible joint ventures with private prison operators in line with a Government move to open the sector to competition.
Ms Turei says the multi-national companies likely to win such contracts are driven solely by profit, and it's foolish to think they share the Maori interest in rehabilitation.
"These corporations don't care for us. They just want to make a buck," she said.