Former Minister for Whānau Ora Tariana Turia has accused Te Puni Kōkiri of not rolling out the social policy properly - possibly because it did not think it would work.
The outgoing Māori Party co-leader ended her term as Associate Health Minister and Whānau Ora Minister when the new Cabinet was sworn in last week.
Whānau Ora was Mrs Turia's flagship policy and she entrusted Te Puni Kōkiri with its rollout in 2010.
But in an interview with Radio New Zealand News, she said the agency was underspending and it put her in a difficult position when she was asking for more money for Whānau Ora.
"You can't go back to the Government and ask for more money when your agency is underspending. You simply can't. They want to know, 'Well why are they underspending and what happened there?'.
"So you get every excuse in the book - but the fact is, it should never have happened. I asked them why they underspent and they had every excuse in the book and none of them I bought.
"I think that it was just very poor, it was a poor rolling out of Whānau Ora and a lack of understanding or belief that Whānau Ora could work, actually."
Mrs Turia said Finance Minister Bill English believed the programme could make a difference. However, there was not the investment in it, and that was not helped by the ministry not spending the money it had been given.
Mrs Turia said she took some money off the Ministry of Māori Affairs and put it into three commissioning agencies after the incidents occurred.
"I guess my determination, and it will still be my determination - I don't need to be a politician or to be in Parliament - is to see that those agencies do not get focused on organisations [but] that they do get focused on making the changes for families, and that the resources should get as close to family as possible if we want to make the difference.
"I fixed a problem just before I finished. That was to encourage people to understand that Whānau Ora does not need to be delivered by a service provider - that there are other organisations, family collectives, family trusts and marae who already deal with people in family settings who could be doing really important jobs."
Mrs Turia said Māori on the ground were better equipped to implement the Whānau Ora kaupapa.
"They won't have the infrastructure costs, they will also be more connected and engaged with those families and they will know them intimately, they will know the issues that are confronting those families and I think that they will be able to help those families to pathway into their future in a far more constructive way."
Te Puni Kōkiri agency refused to be interviewed but released a statement attributed to chief executive Michelle Hippolite.
"The commissioning (agencies) model announced in July last year was a result of work started after a Relationship Accord in 2011 agreement between the National Government and the Māori Party."
The agency said there was underspending.
"As Whānau Ora was reviewed, there were occasions when it was inappropriate to commit funding when the future development of the Whānau Ora approach was unclear, and in those years there was an underspend. However, that money was moved from one year to another, not lost. "
The agency also said no money has been taken away from Vote Māori Affairs and Te Puni Kōkiri is still responsible for all Whānau Ora funding.
Te Puni Kōkiri claims to have spent more than 99 percent of the $150 million funding it has received from 2009 until 30 June 2014.