Japanese whalers have suspended their hunt in the Antarctic, citing harassment by environmentalists, and are considering ending their annual mission early.
An official from the Japanese Fisheries Agency says the factory ship Nisshin Maru has suspended operations since 10 February to ensure the safety of the crew.
Activists from the US-based Sea Shepherd Conservation Society have pursued the Japanese fleet for months to stop its harpoon ships from killing whales, AFP reports.
Sea Shepherd Captain Paul Watson has confirmed that the Nisshin Maru is now sailing in waters far from the hunting area.
He estimates the whalers have got no more than 30 whales this season.
Japan kills hundreds of whales a year under a loophole in a 1986 moratorium on commercial whaling that allows "lethal research".
Anti-whaling nations, led by Australia and New Zealand, and environmental groups believe the hunts are cruel and unnecessary.
Australia has started action against Japan over whaling in the International Court of Justice.