Key Points:

Japanese whaling ship the Nisshin Maru has restarted its engines and left the Ross Sea.

The Nisshin Maru is the mother ship for a whaling fleet run by the Japanese government-affiliated Institute of Cetacean Research, which was hunting whales in the Southern Ocean when fire broke out on it 10 days ago. One crew member died in the fire.

Institute spokesman Glenn Inwood -- a New Zealander based in Japan -- said all vessels in the fleet were refuelled yesterday, after which "they took off".

"What they need to do now is they need to make some adjustments in terms of navigation, steering, those sorts of issues, they need to actually just test the vessel under working conditions as it sails along," he told NZPA.

"They're going to do that for a few days and I think mid next week we'll probably make a decision on 'should I stay or should I go now'."

Mr Innwood hinted that it was likely they would stay and carry on whaling, saying he had seen a Greenpeace statement saying it would escort the fleet out of the Antarctic.

"Well, they're only going to be escorting themselves at this stage," he said.

Mr Innwood also had some harsh words for Maritime New Zealand (MNZ), which would have co-ordinated a rescue effort should it have been needed and which had been monitoring the situation.

"Maritime New Zealand all week have been behind the times and I am tired of them making ridiculous claims," he said.

"I saw them yesterday (reported as) saying 'as far as we're aware the engines haven't been started'.

"The proof is in the pudding. We're not there."

MNZ spokeswoman Julia Lang told NZPA it had daily calls with the Nisshin Maru and that its latest advice -- received yesterday afternoon -- was that the engines had not been started.

The Nisshin Maru was supposed to notify MNZ if they started the engines but had clearly failed to do so as this morning's advice was: "They're not on the move."

Meanwhile, Greenpeace has called on the international community to ensure that the fire-damaged Japanese whaling ship the Nisshin Maru never returns to the Antarctic.

The Japanese steadfastly refused offers of help from Greenpeace, whose protest ship Esperanza is now shadowing it out of the region.

"Greenpeace is relieved that, after nine days, the whaling factory ship Nisshin Maru and the rest of the whaling fleet is finally leaving the pristine environment of the Southern Ocean," Greenpeace Australia chief executive Steve Shallhorn said in a statement.

"The international community must now ensure that this sub-standard fleet never returns to place the Antarctic environment and marine life at such risk again."

Mr Shallhorn said the Nisshin Maru had been damaged by fire once before and none of the Japanese whaling fleet vessels was ice class, despite routinely operating in icy conditions.

"The Japanese government does not file an environmental impact assessment when the whaling fleet operates in Antarctica," he said.

"While there is no legal obligation to do this, as a signatory to the Antarctic Treaty, the Japanese government does have an obligation to follow the spirit of the international agreement and their whaling operation shatters both the spirit and intent of the treaty."