Australia's $20 million legal bid to end Japan's ''research'' whaling in the Antarctic is set to begin hearings against a determined defence led by a top Japanese official.
Deputy Foreign Minister Koji Tsuruoka, a career lawyer-diplomat, will lead its delegation at the International Court of Justice in The Hague, a Japanese government source said.
Mr Tsuruoka was recently appointed as Japan's chief negotiator for the Trans Pacific Partnership economic agreement between Pacific rim countries, including Australia, Kyodo news agency said.
Japan will challenge the court's jurisdiction to hear the case, as well as rejecting the Australian legal argument that the hunt contravenes the global treaty on whaling, ANU international law professor Don Rothwell said.
The case opens on Wednesday with Australia's oral evidence. Attorney-General Mark Dreyfus said he would appear before the court in the four-week hearings.
''The ICJ expects senior ministerial representation by countries bringing cases before it, which is why I will be there,'' Mr Dreyfus said on Sunday.
Australia launched the case in 2010, asking the court to halt a hunt that violated the International Convention for the Regulation of Whaling laws's moratorium on commercial whaling, and was on a scale far beyond the convention's rules on killing whales for research.
Japan has killed more than 14,000 whales using the scientific research clause since the moratorium was introduced in 1986, according to the International Fund for Animal Welfare.
The Japanese government annually issues a scientific permit for a quota of up to 935 minkes, 50 fin whales and 50 humpbacks, with the humpback quota currently ''suspended''.
Its whaling fleet is meeting increased conservationist pressure in heated clashes that have brought the most serious conflict ever seen in the Antarctic.
This year the whalers returned to port with 103 minke whales, the lowest-ever tally, blaming pressure from the ships of Sea Shepherd Australia.
Mr Dreyfus said he believed the $20.4 million cost of the ICJ case so far, revealed in budget estimates, had the support of Australians.
''This is a complex piece of litigation requiring a lot of preparation,'' he said.
To argue the case, Australia has marshalled a high-ranked group of international law experts including Adelaide-born Cambridge University professor James Crawford, SC, Briton Philippe Sands, QC, and France's Laurence Boisson de Chazournes.
Japan is yet to announce its legal team.