One of the country's largest iwi says the Government would be abdicating its responsibility for vulnerable tamariki if parts of Child, Youth and Family were privatised.
Ngāti Kahungunu said it was alarmed Prime Minister John Key was not ruling out some of its responsibilities being shifted to the private sector.
There has been a groundswell of opposition to Mr Key's comments, with some academics, Māori leaders and welfare advocates voicing concern at the possibility.
Its chairman Ngahiwi Tomoana said if elements of its services were shifted to commercial groups it would be terrible for tāngata whenua, who were over-represented as CYF clients.
"It's a huge backward flip, it would take us back 100 years. I don't think that should happen at all, I think the Crown should front up with its Treaty partners and discuss and explore and evolve ways to improve the system," said Mr Tomoana.
"We're here to help the Crown, we're here to help them save money and we're here to help our whānau save lives, and I don't think we're going to do that by abdicating responsibility to a group that is primarily concerned with making money - so that's alarming."
Mr Tomoana said making money out of people's and tamariki's misfortunate was a very risky and dangerous business.
"Especially when we have a whole new generation being born in prison, that is frightening in itself, and to have them born under a commercial model run by foreigners is just appalling."
In a statement Social Development Minister Anne Tolley said:
"CYF currently has four MoUs with iwi, and is trialling Mokopuna Ora with Tainui, which is aimed at ensuring fewer mokopuna need to come into the custody of the ministry, and where they do, they are connected and supported by their iwi.
"Any decision on taking children into state care will always lie with the state. The current system isn't working for our vulnerable children, which is why it requires a complete overhaul.
"An expert panel will provide a detailed business case on this by the end of the year.
"This panel also has a Maori Reference Group to provide advice."
In May, the chair of the Whānau Ora iwi leaders group, Raniera (Sonny) Tau, wrote to Social Development Minister Anne Tolley to express the group's 'extreme concern' at the panel's make-up which appears to contain no Māori.
Mr Tau said he was appalled by the lack of Māori representation.