Random tests find Semtex

Two taxis based at Heathrow Airport were found to have traces of Semtex explosive by scientists carrying out random tests.

The discovery, which took the scientists by surprise, came during a Home Office study to assess the risk of innocent people becoming terrorist suspects through accidental contamination.

Traces of the Semtex constituent RDX were also found on a luggage handling surface at Heathrow.

The study, reported in the Journal of Forensic Sciences, was conducted by the Defence Evaluation Research Agency's forensic explosives laboratory at Fort Halstead, Kent. A spokesman said: "One possibility is that the taxis had carried a service person or somebody who dealt with explosives in a commercial capacity."