AUSTRALIAN Federal Police are expected to raid the Sea Shepherd ships on their return to Australian waters after clashes in the Southern Ocean.

Police are tipped to swoop when the ships arrive in Hobart in coming days, The Mercury reports.

The news came as the anti-whaling group yesterday said it hoped the whaling season was over as the Japanese fleet headed north.

The whalers were well out of Australia's whale sanctuary and Sea Shepherd Australia director Bob Brown said it was highly likely the hunt had ended with fewer than 100 whales killed, probably the lowest tally in 200 years outside world wars.

But if Sea Shepherd ships, which are tailing Japan's fleet, arrive in Australia - probably in Hobart - they are likely to face Australian Federal Police raids.

Australian National University professor Donald Rothwell said Japan was likely to request the raid after the incidents at sea involving Sea Shepherd and Japanese vessels.

"Given the events we've heard about, I'm sure Japan will have made a request for Australia again," Professor Rothwell said yesterday.

On top of that, if Sea Shepherd observer Paul Watson subject to an Interpol red notice is on board, he faces arrest if Japan requests extradition.

The whaling season is due to end this month and Dr Brown and Mr Watson said they hoped it had ended.

"(The fleet's) been steering north for two days now and moved out of the whale sanctuary," Dr Brown said in Tasmania.

"Both groups of Japanese ships are being followed by our ships.

"The whales themselves are beginning to migrate and the plankton is rapidly diminishing. It's very, very good news but not absolute yet."

The Institute for Cetacean Research said that it conducted its Antarctic whale research program under a permit issued by the government of Japan in accordance with the international convention for the regulation of whaling.

It has repeatedly said that Sea Shepherd ships have endangered the safety of whale research vessels.

Barring an early decision by the International Court of Justice, the whalers are expected to be back at work in December.

Professor Rothwell said even if the case began shortly, a decision was not likely until next year.

If the court did find in Australia's favour, he felt certain Japan would abide by the law.

"I find it inconceivable that Japan might ignore a ruling," he said.

The court has 15 judges and would decide whether or not commercial whaling was being carried out.

If so, it would be contravening international convention.

For more see The Mercury

Originally published as AFP tipped to raid Sea Shepherd ships