Japan's whaling fleet in the Antarctic will avoid killing humpback whales for now, but will press on with plans to kill 1,000 other whales by early in the New Year.

The move follows Australia's announcement on Wednesday that it would send a fisheries patrol ship to gather evidence for a possible International Court challenge to halt Japan's yearly slaughter.

Plans by Japan to include 50 endangered humpbacks in its annual hunt had sparked an outcry from activists.

Popular among whale watchers for their distinctive silhouette and acrobatic leaps, humpbacks were hunted to near extinction until the International Whaling Commission ordered their protection in 1966.

A government spokesman has decided not to catch humpback whales for ‘one year or two’.

Australia, Britain, France and Germany were among 30 nations who lodged a joint diplomatic protest with the Japanese Foreign Ministry today over Tokyo's annual whale hunt.

Japan's whaling fleet set sail last month with plans to catch more than 1,000 whales including 50 humpbacks. It is due back early next year.