SYDNEY (AFP) - Activists hunting a Japanese whaling fleet in the icy waters of the Antarctic will pay a reward of 25,000 dollars to anyone who can help them find the elusive ships, their leader has announced. Sea Shepherd president Paul Watson told AFP in a satellite telephone interview from his flagship, the Farley Mowat, that the Japanese were using satellite technology in a high-seas game of hide-and-seek with their pursuers."We know they bought a 150,000-dollar ship tracking programme, so we suspect they can see us through the satellites," said Watson, who has been searching for the whalers in the Southern Ocean for three weeks."We're taking some steps to try to avoid the satellites. We know what time they fly over, so we, you know, try to hide behind an iceberg. But the thing is we are really at a disadvantage."Watson, a Canadian-born activist who has been accused in the past of using violent tactics in his conservation efforts, has threatened to use a ram to punch holes into the six whaling ships and force them back to port.But time is running out. If Watson and his two-ship expedition can't find the Japanese fleet in the Southern Ocean within the next two to three weeks they will have to return to port to refuel.Watson's offer of a reward for information on the location of the fleet was apparently prompted by the New Zealand government's release last Friday of footage of the Japanese fleet harpooning and cutting up whales.New Zealand opposes Japan's whaling but has refused to disclose the exact location of the fleet, with Environment Minister Chris Carter having expressed concern about Watson's threats against the whalers.Watson told AFP that New Zealand's refusal to provide the fleet's geographical co-ordinates "makes them complicit in a Japanese crime".He said he hoped somebody with access to the information -- "either in New Zealand or through satellite programmes" -- would provide it in return for the 25,000-dollar reward.The International Whaling Commission imposed a moratorium on commercial whaling in 1986 but Japan has continued hunting for what it calls scientific research. Critics reject this claim, and Japan makes no secret of the fact that the meat from the hunt winds up on dinner plates.The Japanese ships are on an expedition during the Southern Hemisphere summer this year to kill about 850 minke whales and 10 fin whales, the Japanese Fisheries Agency has said.