The Brazilian oil company surveying the seabed off East Cape has temporarily stopped its operations, after protesters swam in the path of its survey vessel, The Orient Explorer.
Petrobras was awarded a permit last year to explore 12,000 square kilometres in the Raukumara Basin for gas and oil.
Five boats with about 50 activists on board have been in the Raukumara Basin since two Petrobras vessels started surveying there a week ago.
The company stopped its explorations at about 2pm on Sunday, saying it was unsafe to work while protesters were in the water.
Greenpeace spokesperson Steve Abel says that diverts the ship off course, rendering the data it is collecting useless.
But Petrobras spokesperson Mark Blackham says the protesters are not having a huge impact on its operations, as surveying is expected to take up to 60 days.
He says it is not known when Petrobras will restart its surveying.
Maritime New Zealand says it is monitoring the situation by listening to radio communications.
