Japanese whalers say they hope Sea Shepherd activist Paul Watson will be arrested as the marine conservation group prepares to confront their whaling fleet in Pacific waters.
Mr Watson has for years frustrated Japan's whaling efforts in the Southern Ocean, using ropes to foul the engines of Japanese vessels, hurling rancid butter stink bombs at them, and even allowing his crew to board Japan's ships.
But this year Mr Watson faces grave legal issues after skipping bail during an extradition hearing in Germany and is the subject of an international wanted persons alert through Interpol.
"I think Paul Watson has been doing illegal activities and put serious risks (sic) against our researchers, and I hope he is arrested," said Makoto Ito, a spokesman for Kyodo Senpaku Kaisha, which owns the whaling fleet.
He hoped Sea Shepherd would not succeed in any attempts to hamper Japan's fleet.
Mr Ito said Japan planned to take 900 whales this year in its annual whale hunt, including 850 minke whales and 50 fin whales, which are endangered.
He said he knew of no plans for Japan to send its coastguard to Antarctic waters, as they have in the past, or if Japanese authorities would take direct action to apprehend Watson.
Sea Shepherd ships and Japanese vessels have collided in the past, although both sides blamed each other for the strikes.
Sea Shepherd this whaling season hopes to prevent Japan from taking a single whale, and its first vessel is expected to leave from Melbourne at 4pm (AEST) on Monday.
For the first time Sea Shepherd is expected to meet the whaling fleet in the North Pacific off Japan, rather than wait for the Japanese to get to Antarctica.
Andrea Gordon, 34, ship manager of Sea Shepherd's Bob Barker, which is due to head north from Sydney next month, said she was eager to ensure Japan did not take a single whale this year.
"I feel very determined to stop the whaling fleet," she said.
Ms Gordon said Sea Shepherd was twice as strong as it was last year, with four vessels and 100 crew, and had named this year's protest Operation Zero Tolerance.
Japan uses a loophole in International Whaling Commission rules that allows whales to be killed for scientific research.
Mr Watson fears extradition to the South American nation of Costa Rica, where he faces 10-year-old allegations that he endangered a vessel allegedly involved in shark finning.
A spokesman for Japan's Institute of Cetacean Research in Tokyo refused to answer questions about this year's hunt.
"We have nothing for Australian journalists," he said before hanging up his phone.