22 June 2012 Last updated at 11:33 ET

Gang behind Southampton £300m cocaine seizure jailed

By Joe Lumley BBC News, Southampton

UK border force officers found the drugs in a specially-built compartment

When the 65ft luxury motor yacht the Louise arrived in Southampton it had enough cocaine hidden on board to sustain a third of the annual UK market.

The gang behind the plot aimed to flood Europe with up to £300m of the Class A drug, the equivalent of about seven million street deals.

But the conspiracy was smashed after authorities, who had received a tip-off, intercepted gang members' telephone conversations with a wire tap and tracked the pleasure cruiser from the Caribbean to the UK.

Border force officers discovered one tonne of 90% pure cocaine, one of their biggest ever seizures, hidden in a deep compartment, during an almost week-long search of the yacht.

The haul accounted for almost half of the total cocaine seizures across the whole of the UK in 2010/11, which was 2.4 tonnes.

When the smugglers were arrested in a series of police raids across the Netherlands, officers recovered a loaded machine-gun, a handgun with silencer and 1.5m euros.

'Ingenious' hiding place

French authorities were first alerted that a shipment of cocaine had been loaded on to the Louise in May last year.

The Louise was tracked from the Caribbean to Southampton, where it arrived later that month, after being transported aboard a container ship along with other luxury cruisers arriving from the Caribbean for the UK summer season.

Border force officers, who spent six days searching the yacht with sniffer dogs, eventually discovered the cocaine bagged up in a deep compartment, specially designed for smuggling, beneath the diving platform.

Drugs being smuggled out of the Caribbean and South America on boats are usually hidden among tropical fruit, the border force said.

At the time of the discovery Brodie Clark, then head of the border force, described the hiding place as "ingenious".

The cocaine, destined for the Netherlands, via England, was packed inside the boat while it was in Venezuela.

The haul was estimated to be worth about £50m wholesale and up to £300m on the streets.

The border force helped Dutch police track the gang to the Netherlands, which led to the Dutch defendants - referred to in court only as Klaas L, Mohamed Z and Robert L- being charged.

Klaas L, 61, owner of the Louise, and Mohamed Z, who handled all of the plot's finances, both headed up the gang, Dutch prosecutors confirmed. Both have former criminal convictions, but not for drug smuggling.

Klaas L, from the northeast of the Netherlands, was arrested, along with his son Robert L, 33, from the south of the country, following police raids.

When officers arrested Mohamed Z at his home in Amsterdam, they found 1.5m euros (£1.2m) and a loaded machine-gun. Two Harley Davidson motorcycles, a second firearm and a silencer were also seized.

The gang had been waiting in the Netherlands for the drugs shipment to arrive.

Money laundering

The three defendants were convicted of being involved in the transportation of cocaine.

Klaas L was also convicted of laundering 60,000 euros (£48,000). He was jailed for seven years.

Robert L, who was also convicted of possession of a firearm, was jailed for five years; while Mohamed Z, 45, who was also convicted of laundering almost 1.5m euros but acquitted of possession of a loaded firearm, was jailed for eight years.

Arjan L, 35, another son of Klaas L, walked free from court after being acquitted of drug smuggling.

The convictions come just days after 400kg (882lb) of cocaine with a street value of about £20m was seized from a yacht off the Isle of Wight on 10 June. Two people have been charged in connection with the conspiracy.

Another seizure of cocaine, with an estimated street value of £3.3m, was intercepted by the border force from a container ship docked in Portsmouth in April.

In 2009/2010, the border force seized about two tonnes of cocaine in the UK during the whole year, and 2.4 tonnes of cocaine in 2010/11.