When the breakaway region of Abkhazia split from Georgia in 1993, the world's only known case of enriched uranium going missing was reported after up to 2kg of the potentially devastating material was stolen from a laboratory.

There are now fears that the organised criminal gangs that are rife in the region could exploit the confusion of the current conflict to loot other stocks.

Security services are worried that terrorist organisations such as al-Qa'eda could purchase weapons grade uranium and mix it with a detonator as basic as fertiliser to make a deadly device. While an estimated 15kg of uranium is needed to make a nuclear bomb just a small amount is needed for an unconventional device.

'There is no fear of a nuclear bomb coming out of this region but the bigger danger is that a small amount of uranium combined with conventional explosive terrorists could make a dirty bomb that would make an area the size of the City's Square Mile unusable for 30 or 40 years,' said a security source. 'The economic impact would be catastrophic.' ....