A disabled Japanese whaling vessel has restarted its engines and sailed under its own power, a whaling official said.
The Nisshin Maru is the whaling fleet's only processing ship
The Nisshin Maru, the whaling fleet's only processing ship, had been without power off the Antarctic coast since an onboard fire 10 days ago.
A spokesman for the whalers said the fleet would decide on Wednesday whether to continue or to return to Japan.
New Zealand had warned of international condemnation if the stricken ship leaked fuel into the environment.
The ship is carrying 1.3m litres of fuel oil and was stranded only 100km (60 miles) from the world's largest colony of Adelie penguins.
But it rejected the offer of a tow out of the area from Greenpeace, prompting New Zealand's Prime Minister, Helen Clark, to speak out.
'Peaceful direct action'
Activists hoped that the damage to the Nisshin Maru would force the six-ship fleet to abandon its hunt.
"The Nisshin Maru is moving northward at the moment, away from the coast," said Glenn Inwood, who speaks for Japan's Institute of Cetacean Research.
The whalers planned to spend two or three days checking systems on the ship, he said.
"By Wednesday they expect to make a decision to either stay or leave the Antarctic," he told the Associated Press news agency.
Greenpeace activists are shadowing the fleet on the anti-whaling ship Esperanza.
Karli Thomas, a spokeswoman on board the Esperanza, confirmed that the Nisshin Maru had detached from two other ships to which it had been lashed and sailed briefly under its own steam.
She said that Greenpeace hoped the whalers would leave.
"If they attempt to start whaling again then we will take peaceful direct action to stop the hunt," she said.
Japan is strongly opposed to the international ban on commercial whaling. It hunts whales every year under what it describes as a scientific research programme.
This year Japan says it plans to cull 850 minke whales and 10 fin whales.