Anti-whaling organisation Sea Shepherd has claimed that the Japanese whaling ship "attacked" its ship in the dark in what it described as a "ruthless assault."

According to reports, the Japanese whaling fleet had allegedly disabled the Sea Shepherd ship in the Southern Ocean. The anti-whaling organisation based in Australia said two Japanese whaling ships had ambushed its ship, Bob Barker, on Feb 23. The Japanese whaling ships had allegedly tried to jam the Bob Barker's propellers and rubbers.

The Sea Shepherd called the latest move by Japanese whaling ships as a violation of maritime laws regarding the prevention of sea collisions.

Peter Hammarstedt, captain of the Bob Barker, described what happened during the night of the attack. He said he had been following the Japanese whaling ship Nisshin Maru since the morning of Feb 23. The captain believes the Japanese crew had waited until nightfall to "launch their onslaught."

Mr Hammerstedt commended his crew of nine Australians and one New Zealander for braving the attack on their ship. The captain said their ship was pelted with ice by the Japanese crew who also flashed blinding searchlights to allow the escape of the Japanese whaling ship.

According to reports, two other ships of the Sea Shepherd are currently tracking the Japanese whaling fleet. This is the second time the Sea Shepherd and the Japanese fleet have come to blows in a month.

A video of the collision between the anti-whaling ship Sea Shepherd and a Japanese harpoon vessel has been released to the public earlier in the month. Both the Sea Shepherd and the Japanese Institute of Cetacean Research have released footage with statements that the other did it intentionally.

A shipping expert watched the video of the collision and concluded that the encounter was "probably unintentional." Marine risk consultant John Riding analysed both videos and declared the collision was not intentional. Mr Riding, who is based in Wellington, said the videos show a classic example of "interaction."

The release of the collision videos came following the Sea Shepherd's accusations against the Japanese whaling ships of launching attacks on Bob Barker and Steve Irwin, both vessels in the Southern Whale Sanctuary on Feb 1.