LONDON (AFP) - Police have seized Britain's largest ever cocaine haul, worth up to 300 million, from a luxury yacht which had sailed from the Caribbean, officials said Wednesday. The 1.2-tonne stash was found hidden under the bathing deck of the pleasure cruiser docked in the port of Southampton in southeast England, Britain's Serious Organised Crime Agency and UK Border Agency said. Police believe the drugs were loaded onto the boat in Venezuela. In dawn raids Tuesday Dutch police, acting on intelligence from British and French authorities, arrested six men suspected to be involved in an intl drugs ring responsible for the shipment.