First we had the “shoe bomb” made infamous by Richard Reid, the “shoe bomber” who attempted to blow up an American Airlines flight from Paris to Miami in December 2007. Then we had the “underpants bomber”, Umar Farouk Abdulmutallab, who sewed explosives into his underwear, and tried to blow up a Northwest Airlines aircraft on its approach to Detroit in December 2009. Now we have the spectre of a “shirt bomber”.

US Government officials revealed in August that Al Qaeda have developed a liquid explosive in which clothes can be dipped to become explosive devices when dry, which could be used to perpetrate terrorist attacks and bring down aircraft. The new liquid explosive has apparently been developed by the notorious Al-Qaeda bomb maker Ibrahim al-Asiri who made the device used by the Al-Qaeda “underpants bomber”. It is understood that US intelligence services intercepted Al-Qaeda communications in the Yemen which discussed the use of liquid explosives on clothing to perpetrate a terrorist attack.

According to security experts, the liquid explosive, if soaked into a shirt, would be undetectable by standard airport security scanners, which use imaging technology to safely screen passengers for any concealed items. The shirt or item of clothing dipped in liquid explosive, when dried out, could be ignited by a suicide bomber on board an aircraft by simply lighting a match. The use of liquid explosives on clothing could mean that any air passenger is a potential terror suspect, and would make the prevention and detection of such “clothing devices” by airport security staff nigh on impossible.