The Air Force has spotted an illegal Spanish fishing trawler sailing in the Southern Ocean.
The Bigaro is on a list of blacklisted vessels found to have illegal, unreported and unregulated fishing.
It has been sighted by an Air Force Orion sailing this week within a conservation area near Antarctica.
The sighting has prompted Foreign Minister Murray McCully to urge the Spanish government to take action.
He says Spain cannot afford to turn a blind eye to the company that owns the vessel.