Following "repeated harassment' by US activists, Japan has abandoned its annual Antarctic whale hunt before the end of the season.
Japanese officials confirmed that the whaling boats would return home as the Sea Shepherd Conservation Society (SSCS) made it impossible for them to continue. The four Japanese boats with 180 crew members will be returning a month ahead than earlier scheduled.
The hunters have already killed 170 minke whales, a fifth of the intended target catch of 850.
According to Japanese fisheries minister Michihiko Kano, it had become difficult to secure the fleet's safety. He added the boats had no choice but to cut short their research.
The past few weeks have seen the protesters from the international non-profit organisation hurl red paint, smoke bombs and rancid butter in bottles toward the whaling ships.
The protestors also caused one of the vessels to slow down after getting its propeller entangled in a rope.
The hunt had to be temporarily halted last week when the mother ship, the Nisshin Maru was chased by the campaigners for 2,000 miles.
This is the first instance of Japan ending a whaling ahead of schedule, on activist pressure.