Environment Minister Amy Adams has rejected Labour Party criticism that she has downplayed the risks of deep sea drilling.
Labour's environment spokesperson Moana Mackey says when Ms Adams was questioned in Parliament about a possible spill she replied it might have an environmental impact.
But Ms Mackey says papers obtained by Labour under the Official Information Act reveal an oil spill would be catastrophic for New Zealand.
She says while officials believe there is a low risk of an accident, the further out to sea drilling occurs the greater the risk.
The paper also says the knowledge about the geology, types of hydrocarbons and pressure profiles in ultra-deep water wells is still not thoroughly developed.
But Ms Adams said on Wednesday when she made her comments, she did not have the briefing paper in front of her.
"Of course it would be a terrible event, but the point I was making is that the risk of that occurring was regarded as low, which is what the briefing bore out.
"So I think she's playing a bit cute with the choice of words. I was never purporting to quote the document. There's no doubt that a spill could have potentially very serious effects - we all know that."
Ms Adams says it is a matter of managing the risk and she is confident the appropriate safeguards are in place.
