Single hair may lead to shoe bomber's engineer

An al-Qaida-linked terrorist known as The Engineer made the exploding shoes that prosecutors say Richard Reid wore in a bid to blow up a transatlantic airliner.

Officials believe that whoever helped Reid may have left evidence behind, including a strand of hair and a palm print in one of his shoes.

Reid, a petty criminal from London who converted to Islam, is being held in a Massachusetts jail awaiting trial.

He was flying from Paris to Miami on American Airlines on December 22 when it is alleged he tried to set off explosives in his shoes with a match. The plane was diverted to Boston, where Reid was arrested.

European investigators suspect Reid travelled to a terrorist safe house in Belgium to pick up the explosives. He then made his way to France to meet a man codenamed The Engineer, an explosives expert who helped design the shoe bomb.

The sophisticated design required no wires or metal, making the explosives virtually impossible to detect by airport security, sources told ABC News who obtained the first photographs of the shoes.

Matthew Levitt, a former FBI analyst and counter terrorism expert, said: "The explosives were extremely sophisticated and there's no question that this was not something he did by himself. Reid was a mule."

ABC said intelligence officials suspect Reid had support from European bin Laden associates.

Investigators believe Reid was helped by terrorists in France and Belgium with ties to Djamel Beghal. He is being held in France and is suspected of planning an attack on the US embassy in Paris.

"The funding, the material, the know-how all indicate that there was someone or some group behind this," said Levitt. "And it appears to be al-Qaida."