The airport has four Rapiscan Secure 1000 scanners, each thought to cost around £60,000, in place in terminal 4, used by British Airways for the majority of its long-haul flights.

The Rapiscan Secure 1000 is unlike traditional airport scanners in that it can detect organic materials, such as explosives, narcotics and ceramic weapons, as well as metal items. Experts familiar with the device says it is easily capable of detecting liquid explosives such as triacetone triperoxide (TATP) and nitroglycerin.

The machine works by scanning the body by analysing the reflections of low energy X-ray beams from the body and any concealed objects. The beams are powerful enough to penetrate clothing but not flesh.

When Secure 1000 scanners were trialled at Orlando International Airport in Florida in 2002, passengers were horrified at the level of detail. In demonstration images frmo the scanner, people appear virtually naked, with details of the buttocks clearly visible and genitalia distinguishable. When BAA, the company that operates most of the UK's major airports, were trialling the new scanners, passengers were only screened by members of the same gender, no visual contact was made between the screener and the passenger and images were permanently deleted once the process was completed.

Both the manufacturer and Heathrow airport are unwilling to talk about the scanners. Rapiscan’s UK managing director would not comment on the capabilities of the scanners saying that they were a matter for the Department for Transport while BAA said it would not comment on security measures in place at its airports.

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