Wellington - New Zealand has joined Australia in the International Court of Justice (ICJ) in a case against Japanese whaling in the Southern Ocean, Foreign Affairs Minister Murray McCully said on Friday.McCully said New Zealand would support Australia's case in the ICJ after diplomatic initiatives have failed to halt Japanese whaling in the region."New Zealand has worked hard with Japan for over three years to try and find a permanent solution to whaling in the Southern Ocean," he said in a statement."The government will continue to use all avenues possible to try to bring a halt to Japanese whaling in the Southern Ocean."Australia filed a complaint against Japan at the ICJ in 2010, arguing that Japan was violating the International Convention for the Regulation of Whaling by killing whales for research purposes. A decision is expected in 2013 or later.In December 2010, the New Zealand government decided in principle to intervene in the case. Intervention is a procedure that enables a non-party to the case to put its legal views before the court.Japan, Iceland and Norway are the only countries to engage in whale hunting. Japan introduced what it described as scientific whaling to skirt the commercial whaling ban under a 1986 moratorium and argues it has a right to monitor the whales' impact on its fishing industry.Anti-whaling activists regularly harass Japanese vessels in their annual whale hunt in the Southern Ocean off Australia and Antarctica, with the two sides sometimes clashing violently. At least one activist boat has sunk in recent years.