Britain abandoned its fight to recover treasure worth £5.5billion from a Royal navy shipwreck near Gibraltar over fears it would upset Spain. HMS Sussex was a Royal Navy flagship lost off Gibraltar more than three centuries ago. It is believed the wreck sits in international waters to the east of Gibraltar, which Britain could claim under international maritime law. In 2001, Odyssey Marine Exploration, the US deep sea exploration company, said it was '99 per cent' sure it had found the ship after a three-year search. The Florida-based Odyssey would also, she said, lose British 'aid' when their ships sailed from the port of Gibraltar, where they were moored.