Dramatic images have been sent from the Antarctic of the Japanese whaling factory ship Nisshin Maru colliding with other ships - including its own fuel-laden tanker.
The 8030-tonne Nisshin Maru can be seen amid pack ice grazing the stern of the 5741-tonne Sun Laurel near Australia's Davis station, in images sent by the anti-whaling group Sea Shepherd.
As a result, the framework for launching the tanker's lifeboat has been damaged, preventing its release in an emergency.
The collision on Wednesday came as the Nisshin Maru attempted to reach the Sun Laurel for refuelling, also hitting the anti-whaling group's long range ship Bob Barker in the stern and disabling it.
During the skirmishing, Sea Shepherd's flagship Steve Irwin was also hit multiple times by the Nisshin Maru, according to the group's founder Paul Watson.
Images show the Nisshin Maru amid drifting ice riding up on the stern of the Steve Irwin.
The group has for the past two days blocked attempts by the Nisshin Maru to refuel from the Sun Laurel.
Comment has been sought from the Japanese Government on the clash.
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Meanwhile the consul-general in Melbourne, Hidenobu Sobashima, said his government's basic position remained the same.
"All obstructive activities of Sea Shepherd that endanger life of the crew and property, and safe navigation at sea, should be stopped," Mr Sobashima said.
Whaling conflict escalates
The Antarctic whaling conflict has worsened sharply, with collisions and some damage reported as activists and whalers dispute the refuelling of the whaling fleet.
After several days of close manoeuvres between the two sides north of Australia's Davis station, Sea Shepherd activists said on Wednesday the factory ship Nisshin Maru had rammed two of their ships.
"The Steve Irwin has been rammed twice by the Nisshin Maru," said the group's founder, Paul Watson.
"The Bob Barker has also been rammed and is taking on water in the engine room. The crew have the situation under control."
Comment was being sought from the Japanese Government, which defends its whaling as a legal activity, and says it is complying with all international regulations governing refuelling in the Antarctic.
The activists have been blockading the whaling fleet's tanker, Sun Laurel, from refuelling the Nishin Maru.
On Tuesday night, Sea Shepherd said small boat crews had cut loose a fender lowered to buffer the Sun Laurel with the Nisshin Maru.
At last report the Bob Barker was said to beholding position between the whalers' ships in heavy ice conditions.
As the drama was unfolding Sea Shepherd's Australian director Jeff Hansen had said they had been blocking attempts by Nisshin Maru to refuel on Sun Laurel.
They claim the tanker, which flies a Panama flag, has never been in the ice before and is now near the main ice shelf.
He said Sea Shepherd’s ships Steve Irwin and Sam Simon were beside the tanker while Bob Barker was blocking the stern slip way of the Nisshin Maru.
"All three harpoon ships are currently circling the group, blasting the ships with water cannons, trying to bully a path through the ice for the Nisshin Maru."
Captain Siddharth Chakravarty aboard the Steve Irwin has said the situation had gone too far.
"The recklessness of the Japanese whaling fleet and the Sun Laurel have put Antarctica's rich environment at grave risk for an ecological nightmare," he said.
"The time has come for the Australian government to intervene and and put a stop to this insanity."