Criticism mounts against 'blood' diamond dealers

The world's largest diamond miner is calling for sanctions against dealers who buy "conflict" or "blood" diamonds diamonds that provide money for rebels in Africa.

De Beers wants the International Diamond Manufacturers Association to expel dealers caught buying the "conflict" stones.

Diamonds from Sierra Leone, Angola and the Congo have fuelled civil wars there. Britain is leading a campaign to ban global sales of illegally-exported diamonds from Sierra Leone.

Sierra Leone has come up with a system to stop the smuggling of rebel-mined diamonds. The government is issuing certificates of origin that identify legally-exported gems.

But dealers say diamonds can be smuggled across the ill-defined border with Liberia. The gems are then exported through that country with an official certificate of origin.

Government officials estimate the rebels earn between $20 million and $60 million a year by selling diamonds smuggled through Liberia.