Deep sea exploration oil drilling off the Waikato coast has been delayed by "technical issues", Texas-based oil company Anadarko says.
The deep sea drilling of an oil well, more than 1500 metres deep, was expected to begin this morning, but by this afternoon had not started, Anadarko New Zealand manager Alan Seay said.
"We're expecting to hear any minute now, but who knows," he said.
"There's technical issues, it's nothing that anyone's doing - it's just the way it goes."
The Oil Free Seas protest flotilla had based itself within the safety zone, off the coast at Raglan, in protest against the 1520m oil well drilling. Mr Seay said their presence was not the reason for the delay.
Greenpeace New Zealand executive director Bunny McDiarmid was on one of the protest boats. She said pipes or casings were still being placed in the sea.
The protesters were not sure how long they would be staying at the scene, inside the 500 metre safety zone, Ms McDiarmid said.
"According to the industry best practice they shouldn't really drill with anyone in the vicinity.
"Our Government and Anadarko have made a big hoo-ha about how incredibly careful they're being and how the industry's been put through the wringer, which frankly is a load of rubbish, so we'll see if they're just going to go ahead and drill."
Yesterday an analysis was released by the Green Party, which claimed the risk of a spill in ultra-deep water - more than 1500m - was as high as one in 19 wells.
The Greens said the risk of a spill had been under-stated; a claim rejected by the Petroleum Exploration and Production Association New Zealand chief executive David Robinson last night.
Prime Minister John Key told RadioLive this morning that some protesters were "genuinely confused by the data and what they're told".
"I think like everybody, they want reassurance that these oil companies are going to do their drilling professionally and to the highest standard.
"I think the way to think about this is, you can't say there is no risk. We've been involved in the oil and gas business for 50 years and there's always been a risk."
However, Mr Key said he believed the risk was "extremely remote".
"I mean we don't, or certainly to this point have never had the kind of pressurised oil conditions that you saw in the Gulf [of Mexico].
"Technology has changed a lot. We have high standards in New Zealand."