Japan says its whaling fleet caught a record low catch of whales during this year's Antarctic hunt blaming "unforgivable sabotage" by activists.

Japan's Fisheries minister Yoshimasa Hayashi says the fleet caught just 103 minke whales and no fin whales, the lowest number since so-called research whaling began in 1987.

Last year the fleet caught 266 whales.

Mr Hayashi blames what he calls "unforgivable sabotage" by Sea Shepherd, with Japan's Fisheries Agency saying the militant conservation group disrupted the hunt four times.

It added that the whaling fleet spent nearly half its time in the Antarctic trying to avoid Sea Shepherd harassment.

The anti-whaling activists committed "unforgivable sabotage", Mr Hayashi said, including a collision with a whaling vessel as it was being refuelled.

"We will seek more support from other countries to conduct research whaling in a stable manner," he said.

The fleet, which left port in December aiming to catch about 1,000 whales, is due to arrive back in Japan this weekend.

Japan's annual whale hunt has long drawn criticism from activists and foreign governments, but Tokyo defends the practice saying eating whale is part of the country's culinary traditions.

Captured whales, later sold as food, are studied as part of a bid by Japan's whaling research institute to prove the mammals' populations can sustain commercial whaling, but activists charge Tokyo uses a loophole to get around an international ban on hunting.

Norway and Iceland are the only nations that hunt whales in open defiance of a 1986 moratorium on commercial whaling.

AFP