Bin Laden 'duped into buying fake uranium'

Osama bin Laden was a long way from producing a nuclear weapon, an analysis of documents, materials and computer disks discovered in Afghanistan has concluded.

Investigators believe Mr bin Laden and his al-Qa'ida network may even have been duped into buying crude containers marked with skull and crossbones, believing they were buying potentially lethal radioactive materials.

More than 110 government buildings, military compounds, terrorist camps, safe houses and caves in Afghanistan have been searched for clues about al-Qa'ida's plans and development of advanced terror weapons. American intelligence officers and special forces found three containers whose contents were considered worrying enough to ship back to America for more detailed analysis.

But the tests found no significant amount of radioactive material in the containers – two seized at the Taliban Ministry of Agriculture in Kabul and one at an al-Qa'ida compound close to Kandahar, according to The New York Times. It may be the containers were dipped in medical waste to mark them with enough radioactivity to trigger a Geiger counter.

"We did not find any type of serious radiological material," said one Pentagon official. "The stuff we found in Afghanistan was not the real stuff. They were swindled, like a lot of other people." Another administration official who has been briefed on the materials seized in Afghanistan told the newspaper: "Their value for a weapon was zero."

Mr bin Laden has made clear his desire to obtain a nuclear weapon for more than a decade. In an interview with a Pakistani journalist, Hamid Mir, last November, he said: "I wish to declare that if America used chemical or nuclear weapons against us then we may retort with chemical and nuclear weapons as deterrent." He declined to say where the weapons came from, or to give any other details.

President George Bush has said he believed the al-Qa'ida leader was developing weapons of mass destruction. In a satellite broadcast to leaders of former Soviet bloc states last November Mr Bush said: "They're seeking chemical, biological and nuclear weapons. Given the means, our enemies would be a threat to every nation and eventually, to civilisation itself."

Most experts believed that while Mr bin Laden did not have the capability to produce a nuclear device, he may have been able to produce a so-called "dirty bomb" – a conventional bomb containing radioactive material that could be spread over a limited area.

The canisters obtained in Afghanistan suggest the network was not ready to develop a weapon even that basic.