Anti-whaling protesters are calling on the government to stop Japanese whalers using charter flights from Australia to spy on them in Antarctic waters.
Planes are taking off from Australian airports to track down the Sea Shepherd Conservation Society's vessel, the Steve Irwin, Fairfax newspapers report.
Flights from Western Australia are reported to have located the Steve Irwin but others from Hobart failed to find the ship.
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The Steve Irwin's captain, Paul Watson, says the aircraft aid illegal whaling in Australian-Antarctic waters.
"They're in contempt of an Australian court order. The surveillance flights should be stopped," Captain Watson told ABC radio.
Call for government action
He also criticised the government's reaction to the reports calling for the parties to act in a sensible, safe manner.
"I think that the government should act responsibly," he said.
"(Environment Minister) Peter Garrett promised before he was elected that this government would stop whaling in the southern oceans and no progress has been made since he was elected. So the responsible thing to do is uphold the law."
Watson said his ship was circled by an aircraft on December 9 just outside Australia's 200-nautical-mile exclusive economic zone south of Albany.
Within hours, a Japanese whale chaser ship latched on to the Steve Irwin, enabling the fleet to track the vessel's movements, he said.
The Steve Irwin captain said the Sea Shepherd fleet was not there to protest against whaling, but to uphold international conservation law against whaling.
Whalers 'same as poachers'
"There's no difference between these Japanese whalers and elephant poachers in east Africa except in east Africa they shoot the poachers," Captain Watson said.
Greens leader Bob Brown, who has also called on the government to prevent the surveillance flights occurring, says an international legal challenge would succeed.
"The prime minister has talked about taking legal action if diplomacy doesn't work, well why doesn't he take the legal action as part of the diplomacy," Senator Brown told the ABC.
It was wrong to compare the surveillance flights to the customs vessel, the Oceanic Viking, which has also previously been used to monitor whaling activity in the south, he said.
"The Oceanic Viking... is very different to surveillance being used to aid and abet the killing of whales," he said.
