NZ and Australia have urged both activists and whalers to calm down
New Zealand and Australia have said they will investigate a Japanese whaling ship's alleged ramming of a protest boat in Antarctic waters.
The whalers and protesters from the Sea Shepherd activist group blame each other for a collision on Wednesday.
No-one was hurt in the incident but New Zealand and Australia called on both sides to avoid activities that could endanger lives.
The activist group said it would continue to harass the whalers.
The Sea Shepherd protest vessel, Ady Gil, is currently being repaired after its bow was demolished in the collision with Japan's Shonan Maru Number 2, which is conducting an annual whale hunt in seas off Antarctica.
New Zealand Foreign Minister Murray McCully said his country's maritime authorities had responsibility for the New Zealand-registered Ady Gil.
"The New Zealand government is totally opposed to Japanese whaling taking place in the Southern Ocean, but we're also opposed to killing human beings down there as well," said Mr McCully.
Japan has complained to Wellington about the collision involving the New Zealand-registered protest boat, top government spokesman, Chief Cabinet Secretary Hirofumi Hirano, said in Tokyo.
Separately, Australian Deputy Prime Minister Julia Gillard ordered the Australian Maritime Safety Authority to probe the incident, which occurred in Australia's area of responsibility for search and rescue.
In recent years the activists and the whalers have regularly confronted each other in the waters around the Antarctic.
THE LEGALITIES OF WHALING
Objection - A country formally objects to the IWC moratorium, declaring itself exempt. Example: Norway
Scientific - A nation issues unilateral 'scientific permits'; any IWC member can do this. Example: Japan
Aboriginal - IWC grants permits to indigenous groups for subsistence food. Example: Alaskan Inupiat
Sea Shepherd spokesman Paul Watson said the incident had turned the confrontations into a "real whale war".
A helicopter from Sea Shepherd Conservation Society's main ship was trying to find the Japanese fleet's whale processing ship and resume attempts to harass the whalers into giving up their hunt, he said.
Japan's Institute of Cetacean Research (ICR), which administers the hunt, accused the Sea Shepherd of using the Ady Gil to attack its vessels.
"The Sea Shepherd extremism is becoming more violent... Their actions are nothing but felonious behaviour," the (ICR) said in a statement.
Japan abandoned commercial whaling in 1986 after agreeing to a global moratorium; but international rules allow it to continue hunting under the auspices of a research programme.
Conservationists say the whaling is a cover for the sale and consumption of whale meat. Current Japanese programmes aim for a total catch of more than 1,000 whales per year.
THE ADY GIL
The Ady Gil, formerly Earthrace, was designed for a successful round-the-world speed powerboat record attempt in 2008. It was acquired by Sea Shepherd last year and renamed after a Hollywood businessman benefactor.
1. The hull is described as a wave-piercing trimaran. It is made out of carbon fibre with a foam core, but has had Kevlar armour added to defend against ice. It is capable of submarining up to 7m (23ft) underwater.
2. Much of the helm was originally modelled on a racing car. It was fitted with racing-style seats and a carbon steering wheel. Its windscreen is 17mm laminated toughened glass.
3. Power comes from two 540 hp engines, and the boat can reach speeds of more than 40 knots (75km/h). It runs on biodiesel fuel and has a range of between 2,000 (2,700km) and 13,000 nautical miles depending on speed.
4. The 14-tonne vessel's distinctive horns act as ducts to channel hot air from the engines and suck in cool air. The interior has space for six beds.
Sources: Sea Shepherd, Earthrace, Craig Loomes Design Group