SYDNEY - AN ANTI-WHALING protest ship collided with a Japanese whaling vessel in the Southern Ocean on Friday as the Japanese tried to haul a dead whale on board, said the anti-whaling group Sea Shepherd Conservation Society.

No one was injured in the collision, which caused minor damage to the stern of the Japanese ship, said the hardline anti-whaling group.

The Sea Shepherd ship Steve Irwin collided with the Yushin Maru 2 as the harpoon vessel tried to block its attempt to prevent the transfer of a dead whale up the slipway of the factory ship Nisshin Maru,' said Steve Irwin Captain Paul Watson.

'We were in the process of blocking the transfer from the Yushin Maru 2 when the Yushin Maru 1 moved directly in front of the bow to block us,' Mr Watson said in a statement.

'I could not turn to starboard without hitting the Yushin Maru 1. I tried to back down but the movement of the Yushin Maru 2 made the collision unavoidable,' he said.

Mr Watson said the collision crushed a railing at the back of the Japanese ship but there were no reports of injuries.

The Steve Irwin ship was continuing to tail the Nisshin Maru to prevent whales being hauled on board.

The Sea Shepherd Conservation Society has been blamed for collisions with the Japanese Antarctic whaling fleet in recent years, as well as high-seas boardings and stink bomb attacks.

Its confrontational tactics have been widely criticised both by pro-whaling groups and fellow environmentalists, although it has also attracted high-profile supporters.

Both the Australian and New Zealand governments oppose the Japanese whale hunt, but have called on whalers and anti-whalers to remain peaceful in the dangerous Southern Ocean.

The annual Japanese whale hunt is aimed at catching about 900 whales. Although Japan officially stopped whaling under a 1986 global moratorium, it continues to take hundreds of whales under a loophole allowing whaling for research purposes. Much of the meat ends up on supermarket shelves and dinner tables. -- REUTERS