"To boycott African diamonds would be a disaster, " said Brown, the former Irish Olympic sailor who has taken a keen interest in Africa since launching his diamond consultancy, diamond. ie.

He worries that the effect of the film on the diamond-buying public will be to discourage them from buying African diamonds at all.

The issue of 'conflict diamonds', is vexing, particularly for consumers who are increasingly concerned that products they buy - whether coffee, clothing or diamonds - come from an ethical, "Fairtrade" supply chain.

Diamond industry representatives have been proactive in trying to counter the publicity surrounding the release of Blood Diamond. They stress that the film depicts events that took place seven years ago in Sierra Leone, that the situation is much improved.

Moreover, they insist that less than 1% of the diamonds being sold legitimately worldwide originate from 'conflict areas' - generally meant as the arc of instability across central Africa that stretches from Sierra Leone to Congo.

In fairness, the industry has taken steps to make it as difficult as possible for illicit diamonds to wind up in your local jeweller or with internet retailers like diamond. ie, launching what is called the Kimberly Process - an agreement among 72 countries that is supposed to require 'rough diamonds', straight out of the ground, only be sold with a certificate vouching for their origin.

While they acknowledge that far fewer conflict diamonds are being sold than five years ago, Amnesty International and other NGOs are using the release of Blood Diamond to raise awareness about the issue. Sceptical of diamond industry claims, they insist that worldwide sales of cut diamond trade is as high as Euro40bn. Even if the percentage of conflict diamonds in circulation is 1%, that could still mean some Euro400m per year is buying grenade launchers and cheap assault rifles, say campaigners.

They also insist that despite the Kimberly Process, banned diamonds from Ivory Coast have been sold through neighbouring Ghana. The diamond industry counters that Ghana has been suspended since October of last year under the agreement.

Despite the uncertainty that lingers over the issue, however, Fraser Brown says the industry has no plans to move towards a system of greater transparency about how diamonds get from African mines to jewellers. Such a scheme would only benefit diamond miners in Canada and Australia, where sophisticated mining operations - including a laser etching process on individual stones - makes their provenance beyond doubt.

Insisting on such precautions would simply mean that Africans dependent on diamond mining would be effectively put out of work, says Brown.