SEA SHEPHERD anti-whaling activists say they have intercepted a Japanese whaling fleet using a military-style drone.

A Sea Shepherd Conservation Society spokesman said they caught up with the fleet 1600 kilometres outside Antarctic waters yesterday.

Second Mate Peter Brown launches the drone from the Steve Irwin. Credit:Reuters/Sea Shepherd

Captain Paul Watson said it would be a long and arduous pursuit to the coast of Antarctica but by using the drone technology, distances could be covered more quickly.

''We now have an advantage we have never had before - eyes in the sky. We can cover hundreds of miles with these drones and they have proven to be valuable assets.''