Police foiled a �40m robbery in May

Three airport employees and their former colleagues were among those held in Tuesday's early morning raids across London, Middlesex and Surrey.

Officers seized a Ferrari and a Porsche, a replica gun and believe the suspects had properties in Spain.

More than 200 officers, some from the Flying Squad and Customs took part.

Four of the suspects have been arrested in connection with a �3.5m robbery of US dollars at Heathrow in February 2002.

Three others are suspected of being involved in a separate multi-million pound robbery attempt which was foiled by police.

High-value shipments

Seven other suspects are alleged to have been involved in smuggling cocaine through Heathrow.

Police say the raids are part of Operation Grafton a crackdown on large-scale crime at Heathrow launched in April 2003.

They estimate tens of millions of pounds of goods, including bullion currency and electrical items are stolen each year from the 200 high-value shipments arriving every day.

Detectives have arrested 97 people, seized six guns and dealt with �150 million of stolen goods during the last 18 months.

Forty airport employees have lost their jobs because of links to organised crime and 24 people have been convicted.

The scheme was launched after complaints from private companies at the scale of their losses to organised crime - one company left and set up at Frankfurt Airport instead.