A power company failed to connect electricity to a home in which five people suffered carbon monoxide poisoning.
Two children, aged nine and 14, were among five people admitted to hospital on Monday morning after a west Auckland home filled with fumes from a petrol generator being used inside.
The group was found semi-conscious by emergency services.
Powershop chief executive Ari Sargent said the family had requested that power be connected to the home before they moved in on Friday.
However, an administration oversight meant that did not happen, Radio New Zealand reports.
Mr Sargent said staff raced around to find an available certified contractor to connect the home, but it was not possible.
The company offered to put the family up in a hotel or motel, but they chose not to take this up, he said.
The five people were taken to North Shore and Waitakere hospitals and were understood to be in a stable condition.
Fire Service spokeswoman Nicole Bernard said they were "sick and vomiting" when ambulance staff arrived.
Auckland Council's building control manager, Ian McCormick, says they were within their rights to be there.
"You don't need a code of compliance certificate to live in a house," he says.
"From our perspective, it's all around safety. We'll get involved if we believe that the living conditions are either dangerous or unsanitary.
"To a certain point, it's up to an individual to make their mind up whether a building is fit to move into."
3 News / RadioLIVE / NZN