Prime Minister Julia Gillard's refusal to intervene in the Antarctic whaling conflict has been rejected by Sea Shepherd as a failure to protect Australian life and property.
Ms Gillard said the government was not empowered to put an Australian vessel between Japanese and Sea Shepherd ships.
''When did we become the nation that apparently has got the capacity to police every ocean in the world?'' she told reporters in Adelaide.
''What we are being asked to consider and do would put Australian personnel at risk.''
Sea Shepherd founder Paul Watson said the government had the authority to police the Southern Ocean against pollution and illegal whaling, and to protect its citizens on the group's Australian-flagged ships.
''Australia sends ships to the Southern Ocean to rescue foreign yachtsmen yet they do not feel responsible for protecting Australian citizens,'' Mr Watson said.
''This lack of action by Australia is really about giving a green light to Japan to increase their violence because they know they will get away with it.''
The Australian Maritime Safety Authority has confirmed that it will be conducting inquiries following Wednesday's clash, in which the factory ship, Nisshin Maru collided with its own refuelling tanker, Sun Laurel, and Sea Shepherd ships.
AMSA said it had reports from the group's Australian-flagged ship, Sam Simon, of interactions between it and other vessels.
''There was no report of loss of life, injuries or pollution,'' the AMSA statement said.
Following the conflict, the tanker Sun Laurel steamed north followed by the Sam Simon, and on Friday the two had halted in the Southern Ocean, Mr Watson said.
Nisshin Maru, followed by the Sea Shepherd ships Bob Barker and Steve Irwin, was about 160 nautical miles from the Sun Laurel and steaming south in bad weather.
Japan's consul-general in Melbourne, Hidenobu Sobashima, said: ''We have temporarily suspended refuelling activities but not more and not less than that.''
News agency AFP also quoted a Japanese Fisheries Agency official in Tokyo saying the whaling program would continue.
The annual Japanese hunt in the Antarctic has in the past continued to mid-March.