As the Japanese whaling fleet neared readiness to depart for its Antarctic hunt, the federal government has again called for its abandonment.
Meanwhile, Conservation group Sea Shepherd said that sea captain Paul Watson, who is wanted by Interpol, is back on board the Steve Irwin.
Mr Watson confirmed he would lead the group's four-ship flotilla against the whalers in the Antarctic this summer.
Environment Minister Tony Burke said that over the many years of its whaling program, Japan had not been able to mount any reasonable argument why its so-called scientific whaling program should continue.
The Australian government launched a case against Japanese whaling in the Southern Ocean at the International Court of Justice in 2010, questioning the scientific validity of the Japanese program. New Zealand joined the case this year.
"I don't think anyone needs to wait for the ICJ [hearing] to know that Japan's whaling should cease," Mr Burke said. "Australia believes commercial whaling is wrong, and we condemn so-called scientific whaling."
Japan's whaling factory ship, Nisshin Maru, was spotted on Wednesday refuelling at sea 14 kilometres off the coast of Akashi in central Japan, Mr Watson said. The ship's location has since been lost by the group.
Mr Watson skipped bail in Frankfurt on July 22. He has warrants issued against him in Costa Rica and Japan.
"The Japanese have certainly put a lot of pressure on me," he said. "The one place I can remain free is on the oceans."
Mr Watson said he would decide whether to attempt to come ashore in Australia after the Antarctic campaign.
"I'll wait until then and figure out what the issues are," he said. "One thing's for certain: if I get to Japan they'll never let me go."
Sea Shepherd changed its mind about meeting the whaling fleet in Japanese waters this season. Instead, Mr Watson said, its four ships would head for a rendezvous in the Pacific.
Sea Shepherd's long-range vessel, the Bob Barker, is headed for Wellington to refuel before going south, Mr Watson said, its fast interceptor Brigitte Bardot recently left American Samoa, and a new ship, Sam Simon, is due in Hobart next week.
Japan's Institute of Cetacean Research does not comment on the movements of its whaling fleet. It conducts its program under International Whaling Commission rules with a self-awarded scientific research permit.
Japan's fisheries agency, which controls the institute, said before a partial refit of the Nisshin Maru began in September there was "no possibility" Japan would miss the Antarctic season this year.