Sea Shepherd Australia released a video today that appears to show one of its ships, 'The Bob Barker', being struck by a Japanese harpoon vessel in the Southern Ocean.

"The Bob Barker was hit by the Japanese whaling fleet's harpoon vessel, the Yushin Maru No. 2 as the harpoon vessel crossed in front of the bow of the Sea Shepherd ship at 67° 29' S 164 °01' W," Sea Shepherd Australia said in a media release published on its website.

According to the organisation, the ship was rammed as part of an "attack" by three Japanese harpoon vessels on the two Sea Shepherd ships, 'The Bob Barker' and 'The Steve Irwin'.

Australia and New Zealand have challenged the legality of Japan's annual whale hunt in the Southern Ocean Whale Sanctuary at the International Court of Justice in the Hague last year and are awaiting judgement on the case.

Australia says more than 10,000 whales have been killed since the start of the international moratorium on commercial whaling in 1986, which was introduced to allow depleted whale stocks to recover after years of overfishing.