An Argentine ship has been caught in Falklands waters 'snooping for oil', the Royal Navy has revealed.

HMS Clyde was scrambled to see off a ship from the Argentine navy thought to be prodding military defences in seas off the Falkland Islands on September 2.

The Argentinian survey ship, ARA Puerto Deseado, switched off her satellite tracker and sailed up to the edge of British territorial waters on Sunday afternoon.

The Royal Navy patrol vessel stationed in the Falkland Islands, HMS Clyde, reacted swiftly after the Argentinian vessel changed course and speed towards the 12-mile territorial limit.

The stand-off ended when ARA Puerto Deseado, bristling with equipment to investigate the depths of the ocean, retreated and turned on her tracker again. She returned to port the next day.