Health Minister Jonathan Coleman has confirmed a Government-initiated independent inquiry into the Havelock North water contamination.
"To ensure we have a clear understanding of what has happened in Havelock North as well as any learnings from the situation, the Government will launch an independent Inquiry," Coleman said.
"This approach has been agreed between the Government and Hastings District Council as the best way forward."
Terms of reference for the inquiry are not confirmed but it would look at events surrounding the outbreak and also the response. It would also consider any wider systemic issues, Coleman said.
"This will be a wide-ranging inquiry to ensure that all New Zealanders can feel confident about the quality of drinking water supplies."
Associate Minister of Health Peseta Sam Lotu-Iiga spoke to reporters on the way in to question time after returning from Havelock North.
Asked if the Government's decision to start an inquiry itself - a move it had earlier resisted - showed a loss of confidence in the council, Lotu-Iiga said a lot had happened in recent days.
"We are about bringing more transparency and more accountability to what's going on in the Hawke's Bay."
He did not directly answer a further question on whether he had confidence in the council.
"Right now, my confidence is based on the performance of the health and safety of local people. And my expectation is that they do the best they can to ensure that.
"People are going to want answers around what happened. And that's why a Government-initiated inquiry is important."
Lotu-Iiga said the possibility of more widespread chlorination of New Zealand's water supplies could be included in the terms of reference.
New Zealand First leader Winston Peters this afternoon issued a two paragraph press release that stated deliberate contamination of the water supply must not be ruled out.
"The reality is the possibility should be in a mix," Peters said.
Lotu-Iiga said that was speculation, and he did not believe there was evidence pointing to a deliberate act.
"We don't know that, and that's why an inquiry is the appropriate thing to do."
Green Party co-leader Metiria Turei said Peters' comments were simply an attempt to get media coverage.
"It is not fair for the people who are up there and suffering right now with this great uncertainty and the economic cost to have those kinds of things being said without cause.
"I think it is insensitive to make these kinds of claims when people are still really ill and really concerned about their health and that of their children."
Turei said she was pleased an inquiry was being held and the immediate priority was to care for residents and find the pollution source.