London: Osama bin Laden's al-Qaida terrorist network has developed a crude radioactive device known as "dirty bomb" in a nuclear laboratory in the Afghan city of Herat, BBC in a report said on January 31.

Citing information from British intelligence agents who had infiltrated into al-Qaida training camps posing as recruits, the report said the terrorist network had a small 'dirty bomb' but not a full blown nuclear device.

It said the British officials had secret intelligence from agents supporting the claim, which included training manuals detailing how to use a 'dirty bomb' to maximum effect.

The bomb has never been recovered but at least one leading al-Qaida weapons expert from Herat is still at large, British officials were quoted as saying.

It said the former Taleban regime had helped bin Laden in developing the bomb by providing him with radioactive isotopes.

The information also proved that Laden's weapons programme was much ahead than anyone thought, officials told the BBC.

Without revealing the actual evidence, which the British officials had provided to the BBC, the report said the information suggested that Laden had taken development of weapons of mass destruction as a priority by 1999.

PTI