Australia said Friday it will launch a formal court challenge to Japan's whaling in Antarctic waters.
The challenge — to be filed at the International Court of Justice in The Hague next week — marks a dramatic escalation in the dispute between the two countries.
Australia has declared the waters around Antarctica to be a whale sanctuary and says Japan's whale hunt there is a violation of its international obligations.
Japan, for its part, says it has the right to carry out what it calls scientific whaling and maintains that many species of whale are abundant enough that its hunt doesn't risk population numbers.
"We will continue to explain that the scientific whaling that we are conducting is lawful in accordance with Article 8 of the international convention for the regulation of whaling," said Hidenobu Sobashima, the deputy press secretary at Japan's foreign ministry.
Artical 8 of the 1946 international whaling convention allows countries to obtain special permits "to kill, take and treat whales for purposes of scientific research."
It isn't clear yet how Australia will frame its anti-whaling case in court. It could argue that Japan is killing far more whales than necessary or that alternate research methods exist that would not involve killing whales.
Australia could also argue that Japan has failed to carry out an adequate study of whaling's impact on the sensitive Antarctic environment.
Alternatively, it could argue that Japan's whaling activities violate environmental protocols of the Antarctic Treaty System, of which Japan is a member.
But any court action would not be quick in coming. An international injunction to stop whaling could take as long as six months. One international law professor at the Australian National University predicted the case might not be settled for four to seven years.
New Zealand officials say they'll decided within a few weeks whether they will join Australia in taking Japan to court.
The 88 members of the International Whaling Commission are currently debating a proposal that would allow some limited whaling under strict quotas.
Japan, Norway and Iceland kill about 2,000 whales every year.