Supermodel Lily Cole, the most recent 'face' of De Beers diamonds, has quit the role after lobbying by Survival International.
The charity, which campaigns for the rights of indigenous peoples, has claimed that the Kalahari Bushmen were evicted from their land to make way for diamond mining by De Beers. After refusing to work for the company again, Cole said: "I was unaware of these matters when I was booked for the shoot."
Cole is not the first model to quit an association with De Beers - Iman did the same last year, again after the charity contacted her. A number of high-profile celebrities have joined the campaign against De Beers, including human rights activist Bianca Jagger and actress Julie Christie.
Survival International has also condemned the Natural History Museum's Diamonds exhibition for ignoring the plight of the Bushmen. The Diamond Trading Company, which is the sales and marketing arm of De Beers, is co-sponsoring the exhibition.
The charity said that when it asked the Natural History Museum to include the experiences of the Bushmen in the exhibition, its request was turned down.
A spokeswoman for the Natural History Museum defended the exhibition.
She said: "This is the world's largest-ever diamonds exhibition - it is unsurprising that single-issue groups such as Survival International should seek to exploit such an event for its own ends.
"We are a non-political organisation, and are not qualified to pass judgement on this issue."