Cocaine from Britain's largest ever cocaine seizure is seen on display in London August 3, 2011. The cocaine, weighing a total of 1.2 tonnes, with a street value of up to 300 million was found hidden beneath the bathing deck of a yacht after a six-day search of a 1 million pleasure yacht at the Southampton docks in June. [Photo/Agencies]

LONDON - After a painstaking, six-day search of a million-pound luxury yacht, the UK Border Agency has seized its largest ever haul of cocaine -- enough to satisfy around a third of Britain's annual demand for the drug.  

The cocaine, weighing 1.2 tonnes and with a street value of up to 300 million pounds, was found expertly hidden beneath the bathing deck of the yacht 'Louise' at Southampton docks in June, the border agency said.

Britain subsequently helped Dutch police arrest six men in the Netherlands and Belgium.  

The cocaine was originally packed into the specially prepared space in Venezuela before the yacht itself was transported from the British Virgin Islands to Southampton in a cargo ship.

With a purity of 90 percent, the seized cocaine is of a much higher purity than the average seized in the UK, at 63 percent.

Along with the cocaine, the UKBA raid discovered a stash of 40,000 euros in cash and a firearm.

The operation involved intelligence provided by Britain's Serious Organised Crime Agency and the help of French customs authorities.