Maori children are being denied their basic human rights, Race Relations Commissioner Joris de Bres said.
The Maori Affairs Select Committee is holding an inquiry into the wellbeing of Maori children.
Mr de Bres this morning told the committee Maori children had basic rights to be free from discrimination, for their language and culture to be respected and nourished, to have an adequate standard of living and to health, education, safety and housing.
"This is not the case for many Maori children at present."
Of the quarter of a million Maori children in New Zealand, a third were living in poverty and hardship, he said.
He called on the Government to engage with Maori, including children, on an ongoing basis, to collect data on progress and the address barriers within public agencies that prevented Maori children having full enjoyment of their human rights.
Unicef spokeswoman Barbara Lambourn said it was disheartening that after years of talking about the crisis for Maori children had not been solved.
"I don't say that there has not been effort but we just haven't been able to achieve the results that we want."
New Zealand society had become more unequal and the solutions would have to be multi-faceted, she said.
But the state had a responsibility to children, who are "our most vital state asset".
There should be a basic standard of care for all children and then targeted assistance for those who most needed it, she told the committee.
Ms Lambourn called on the MPs to have political courage and will.
Regional Public Health team leader Mereana Wilson said the latest news about the Kahui twins showed how important this issue was.
"Those first six months are vital and we only know too well, watching the news this morning with the Kahui twins, how important that investment and supporting of our whanau and our tamariki needs to occur.
"It takes a village to raise a child."
Improving the lives of children started by wrapping support around their parents before they were born, she said.
The committee also heard from education and health experts who called for greater cultural competencies in both sectors.