The Government is considering new measures to protect children from serious child abusers or killers, including court-ordered sanctions to stop some parents from having more children.
Social Development Minister Paula Bennett says she wants to push the boundaries as the Cabinet explores different proposals.
The Cabinet is looking at introducing court-ordered sanctions or legislative changes to stop some parents from having more children, or living or working with children.
Ms Bennett said on Wednesday the thresholds are still being developed, but it could be applied to people who have been convicted for murdering a child, or serious abuse or neglect of a child.
Officials are working on creating some more solid proposals.
The minister says in the past year, 148 children were removed from a parent within days of being born because of concerns about their safety.
Ms Bennett has ruled out forced sterilisation and said the Cabinet has not discussed it. However, she says discussions are being held about how to prevent neglectful parents from being pregnant in the first place.
Ms Bennett says at present, even those who have been convicted for murder or serious abuse or neglect of a child can still live with their children and keep having more.
However, people who have abused or killed dogs can be banned from owning the animal.
The Green Party says the Cabinet is talking about ordering parents not to have more children to deflect attention from what it says is Paula Bennett's position on sterilisation.
Co-leader Metiria Turei told Radio New Zealand's Checkpoint programme on Wednesday that Ms Bennett has discussed the idea in the media.
"She expressed great enthusiasm for the idea of forced sterilisation and did say that Cabinet had been considering just that option. Now, she has corrected herself - but I'm not so convinced that they haven't considered or won't consider it in the future."
The leader of United Future says he is amazed that the Cabinet is even discussing the possibility of giving courts the power to order some parents not to have children.
Peter Dunne says the measures proposed simply go too far.
"I'm astounded that they could even be considering such moves. I think it's fair enough to expect people who are receiving government support to honour some responsibilities in respect of that support back to the state.
"But to intervene in their lives to this extent is, I think, utterly intolerable in a free and democratic society."
Mr Dunne says the courts already have the power to intervene when a child is at risk.
"But to make this a matter of policy that would be applied on a far more widespread basis does remind one of a certain European state in the 1930s. It's probably an extreme comparison, but you do start to wonder about heading down that path."
The group Auckland Action Against Poverty says plans to give the courts power to order some parents not to have children are abhorrent and dangerous.
Spokesperson Sue Bradford says the approach is punitive and unnecessary, as Child, Youth and Family and the courts already have the power to act when a child is at risk.