More than 1000 tonnes of oil has now been pumped off the stricken container vessel Rena since it grounded about three weeks ago.
The 47,000 tonne vessel has been stuck on Astrolabe Reef off the coast of Tauranga since 5 October.
Oil that has spilled from it has contaminated beaches and killed more than 1300 birds.
Salvage crews have been working around the clock, and have cleared four of the five heavy fuel tanks on board the vessel.
On Sunday, work was to begin on pumping from the final tank, in the submerged starboard side of the ship, which holds about 360 tonnes of oil.
But high tides and swells disrupted salvage work on Sunday afternoon.
Salvors have sealed off the area and plan to pump water from around the tank so they can get to a manhole and access the oil.
But Maritime New Zealand spokesperson Kenny Crawford says rough conditions have put that work on hold.
He says emptying the last tank of heavy fuel oil was always going to be the most challenging part of the operation.
Mr Crawford says it's very difficult to put a timeframe on when the tank will be emptied, because the team is at the mercy of the weather.
He says there is still a significant amount of other oil on board such as diesel, hydraulic and lube oil, so work will continue on removing this as well.
The authority says there have been no fresh sightings of oil on the beaches.
However it is following up on reports that oil has reached as far as East Cape.
