A global moratorium on commercial whaling has existed since 1986, but Japan kills hundreds of whales each year under a scientific research programme which opponents decry as commercial whaling in disguise, often with the whale meat ending up in high-end restaurants.
Junichi Sato, from Greenpeace Japan, said "95 per cent of Japanese people have never eaten whale meat or rarely eaten whale meat".
Japan's Fisheries Agency has strongly criticised Greenpeace's action, saying its information is misleading. The agency says only four types of whales are threatened by extinction, and that those swimming off the coasts of Japan are not endangered.
"Anti-whaling people like to use the phrase 'the whale is threatened to extinction'. But if you look it up in an encyclopaedia, you'll see that there's no one such species of whale here," Kesman Hideki Moronuki, a Fisheries Agency official, said.
In clashes between the whalers and activists last year, both sides accused the other of attempting to ram their ships and activists were spilled into icy waters by harpoon cables.
New Zealand's conservation minister on Friday released air force footage of Japanese whalers operating in Antarctic waters.
The footage, shot from a New Zealand air force reconnaissance aircraft, showed two Japanese vessels harpooning whales, then hauling them on board for processing, Chris Carter said.
Meanwhile, Japan has announced that it would host an International Whaling Commission meeting next month as it continues to push for an end to the ban on commercial whaling.
But the absence of 26 anti-whaling nations could cast a shadow over the meeting and threaten the future of the world body.