The ingredients for the bombs match the recommended elements for an explosive device outlined in al-Qaeda documents found abandoned in the basements of houses in Kabul soon after the Taleban and their foreign terrorist acolytes fled the Afghan capital in November 2001.

A reporter from The Times found hundreds of documents, spelling out al-Qaeda’s blueprints for making every type of bomb, from high-explosive devices to improvised nuclear, chemical and biological weapons.

He uncovered huge piles of pages in Arabic, Urdu, Persian, Mandarin, Russian and even English. One of the documents included a list of chemicals found in household products which could produce an effective explosive mix when combined with other elements.

The hand-written formula included using triacetone triperoxide (TATP), also known as acetone peroxide and nicknamed “Mother of Satan” because of its volatility; and also their own version of C4, the military plastic explosive. TATP is a primer for an explosive device.

Security sources indicated yesterday that a version of the Kabul blueprint, based on TATP, had been used by the bomb-maker involved in the London terrorist attacks.

The presence of acetone peroxide stamps a link not only with al-Qaeda but also with previous bomb plots, including the attempt by Richard Reid, the Muslim-convert Briton who tried to blow up an airliner in December 2001, and the plot by Saajid Badat, another Briton,who was arrested in November 2003 after aborting a plan to blow up an airliner with explosives in a sock.

Acetone peroxide was found in the heel of Reid’s black basketball shoes after he was overpowered on board a Boeing 767 American Airlines aircraft in December 2001. There was also an element of PETN, a military-style plastic explosive that can be moulded into any shape.

The al-Qaeda formula for explosives has now found its way into the Leeds homes of the London bombers, although since the shoe-bomber plot and the early designs drawn up in the Kabul documents, there have been many refinements.

The bombs detonated in the Underground and on the bus appear to have been a carefully balanced mix of commercially available materials and military-style ingredients. The evidence of this explosive primer in the four London bombs indicates for the first time that the ingredients were acquired in this country and not brought in from abroad.

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