Brazilian company Petrobras says it cannot guarantee there is no threat to the environment from deep sea drilling off East Cape.
The oil giant is conducting a preliminary seismic survey of 12,000 square kilometres of sea bed off the east coast of the North Island to
determine if oil or gas are likely to be under the ocean floor in commercial quantities.
The company has a licence to search for oil and a legal obligation to continue under the terms of an agreement with the New Zealand Government.
Since Sunday environmentalists protesting against deep sea oil drilling have stopped the operation by swimming in front of survey vessel the Orient Explorer in waters of the Raukumara Basin.
Police on a navy patrol vessel are trying to negotiate with protesters on Tuesday.
Petrobras' asset manager for New Zealand Marco Toledo says the company respects the right to protest, but can not guarantee there are no environmental effects during drilling.
Mr Toledo says the company will continue its exploration when it feels it is safe to do so.
