The anti-whaling group Sea Shepherd says its ships are chasing a Japanese whaling vessel which it has spotted in New Zealand's Ross Sea Dependency in Antarctica.
The group has accused the Japanese of illegally poaching inside the Southern Ocean Whale Sanctuary, where both fleets clashed earlier this month.
The skipper of the Sea Shepherd ship Steve Irwin said it was about 120 kilometres away from the whaling fleet and the environmentalist's other boat the Bob Barker was about 24 kilometres away at 2pm on Sunday.
Siddharth Chakravarty said they wanted to catch up with the whalers to halt their operations by parking one of their vessels across the stern of the Japanese factory ship Nisshin Maru to prevent whales from being transferred to it.
He said the whalers are leaving the Ross Sea, heading north-west.
