Navy ships could be an option to stop protesters interfering with the ship searching for oil in the Raukumara Basin off the East Cape but the Government and the police aren't sure what legal rights they have, Prime Minister John Key says.
The Orient Explorer, owned by Brazilian state-owned oil company Petrobras, is operating under a five-year licence granted by the Government to carry out seismic testing.
Over the weekend swimmers from a protest flotilla of five vessels forced the ship off course by swimming close to it.
No action was taken against them, and Mr Key said today the issue was complicated because the Orient Explorer was a foreign-flagged ship in New Zealand's Exclusive Economic Zone (EEZ).
"New Zealand is a democracy and we respect peoples' rights to protest, but we also respect the rights of other people to carry out legal activities like Petrobras is," he said.
"The police are currently exploring all their options and the police minister is getting advice."
Mr Key said the Crown Law Office had been called in.
"If it was happening on dry land, then the police would be in a position to do something about it," he said at his post-cabinet press conference.
"The question is whether the police are in a position to do something about it when it is in the EEZ, and Crown Law is clarifying that... the position needs to be clarified as to what the police can or can't do."
Police national headquarters said protest activity was being monitored by an air force Orion.
Superintendent Barry Taylor, national operations manager, said they were exploring the available legal options to intercede and would use Defence Force ships and aircraft if needed.
Mr Key said it was his view that Petrobras should be allowed to carry out its seismic work.
"No one is arguing that people don't have a right to protest but when it actually stops the company carrying out what it has been legally granted the ability to do, then that concerns me."
Mr Key was asked whether navy patrols were being considered to protect the Orient Explorer.
He said that could be one of the options "but I wouldn't necessarily say that will be the option".
Greenpeace climate campaigner Steve Abel said protesters were sending an "emphatic message" to the Government that deep sea oil drilling would not be tolerated in the country's waters.
"If we don't stop this initial deep sea oil exploration, rigs could be off coasts all around New Zealand in the near future, each one increasing the risk of spills and fuelling climate change as the oil is burnt."
The Green Party said the Government should not allow exploration for deep sea oil before the industry proved it could plug deep water leaks.
"Without a safety plan, oil drilling off our shores poses an unacceptable environmental, social and economic risk," it said.
Mr Key said the Government was going to introduce legislation that would deal with environmental concerns, and it would be in law well before Petrobras was ready to drill an exploration well, if it decided to do so.
