For a self-confessed and enthusiastic killer of British soldiers there was something strangely naive in the manner of the Taleban bomber. The lightly bearded 23-year-old looked younger than his years, with gentle features beneath his black turban and a habit of asking odd questions.

“The British soldiers have shaved their heads but when we see them washing they are still shampooing their heads, but they have no hair.” He looked mystified and then laughed.

Between the moments of naive curiosity, he boiled with a visceral hatred of Westerners. Almost casually, he mentioned the desire he felt to kill me with a pistol he was carrying, before explaining that he was restraining himself because of a promise he had given to tribal intermediaries who set up the interview.

Instead he focused on his enthusiasm for bombs and dead foreign soldiers and his role as a midlevel commander of 20 to 30 fighters.

“Last year, after one attack near the town of Baramcha, there was the hand of one British soldier left on the field. We took it and we hung it as a souvenir in the room and sometimes we would shake the hand.”

He laughed again.

“We have a new magnetic bomb,” he said. “It is from Pakistan. We put it under the vehicle and then wait till there are many British vehicles together, then just press a button.”

Other bombs he improvised using old munitions and cables from a motorcycle clutch, suggesting perhaps that Taleban bomb supplies were limited.

“We enjoy finding the British bombs unexploded. We have some guys with us, they are not Afghan, they use the bomb back on the British. I like to bury a gas canister on top of the bomb, the explosion is very large,” he added.

“We have some other people with us, I can't tell you where from but they don't speak a language we understand. They have a bomb that recognises the number plate of a vehicle and only explodes with the number plate you put in a computer.” His face betrayed a bemused reverence for such voodoo. The bomber learnt his trade last winter as the Taleban began to appreciate the effectiveness of roadside bomb-making tactics perfected by Iraqi insurgents.

Bombs that he and other Taleban makers have built have killed 34 of the 43 British soldiers killed in the country this year. Many more Afghan civilians have also been killed.

If there was no shortage of bravado about the man, some of his answers also betrayed underlying problems that beset the Taleban.

One was an obsession with spies - suggesting that at least a part of the civilian populace detests the Taleban enough to betray them. “We got two spies last Friday,” he said. “I shot them in the head with 16 bullets each. The spy problem has stopped for now.”

Another problem was how to counter the relentless British pursuit of the Taleban's leadership. It was a particular source of concern since the bomber had been told that he was soon to graduate to a higher level of command - one that would make him of greater interest to Western special forces units tasked with decapitating the Taleban command structure.

“The British give special coats to their spies,” he said. “They have mirrors to show where the planes should go. The spies also drop a tiny piece of metal on the roof of a house. It sends a message and the bomb the house.”

Then, suddenly turning on me, he asked: “When we go to a village at night the British soldiers come for us in helicopters. How can they see us? How do they know we are there? They have technology?”

I shrugged. He nodded.

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