In a statement, the organisation for wildlife protection said the recent launch of a new multi-million-dollar whale-catcher boat showed Japan had stepped up its policy on whaling.

The boat is one of five whalers recently sent into the Southern Ocean - a sanctuary area established by the International Whaling Commission (IWC) in 1994.

It is the 12th year in a row that Japan has sent boats to the region, despite repeated calls from the WWF for it to stop whaling there.

The international conservation officer for WWF-UK, Stuart Chapman, said: "We condemn the action of Japan as it continues to defy the majority of IWC members who for years now have called on Japan to stop whaling in the Southern Ocean Whale Sanctuary."

But the BBC's correspondent in Tokyo, Juliet Hindell, says if whaling were to be banned outright, several thousand people would be out of their jobs, at a time when unemployment is at record levels in Japan.

What's more, many Japanese feel that their country has always been a whaling nation and that whale meat is part of their traditional diet.

In the name of science

The IWC says whaling on the scale practised by Japan is not necessary. It says most research information can be obtained from tissue samples from live whales.

The WWF said Japan had caught 3,767 whales for "research" since 1994 - in April alone the Japanese fleet returned from the Antarctic with 438 minke whales.

Meat from whales caught as part of Japan's scientific programme is sold for high prices on the domestic market. It is even used for school lunches "to try to foster the taste for whale meat among children", the WWF said.

Mr Chapman said Japan - along with other neighbouring countries in favour of commercial whaling - has been trying to set up a regional body to rival the IWC.