TWO BLACK taxis based at Heathrow Airport were found to have traces of explosives. This was revealed yesterday after British Home Office scientists carried out random tests in a study to assess the risk of innocent people being arrested as terrorist suspects because of accidental contamination.
The study revealed that "large amounts of the Semtex constituent RDX and PETN, as well as nitroglycerine, were discovered on the doors, floors and seats on both taxis. "Significant traces" of RDX were also found on a luggage handling surface at Heathrow Airport.
Forensic experts agree that explosive traces are regarded as "significant" if they are above a level of 10 nanograms. The study stated that one of the two taxis had 25 nanograms of RDX on its seats, while five nanograms were found on the doors of the second.
Nineteen nanograms of RDX was discovered on the luggage handling surface in the central search area at Heathrow Airport.
One forensic expert stated that any person who had been in contact with the luggage handling surface would have been "severely contaminated".
Ms Gareth Peirce, the solicitor who represented some of the Birmingham Six and the Guildford Four, said she was not surprised by the study's findings.
Although a British Home Office spokesman admitted officials were "surprised" by the findings, he insisted that in most terrorist eases there was other evidence against the suspect.
The scientists, who were from the Defence Evaluation Research Agency's forensic explosives laboratory at Fort Halstead, Kent, tested taxis, buses, underground trains, police vehicles, police stations, airports and aircraft.