Survival International, the London-based group concerned with the rights of tribal peoples, has called for a boycott of De Beers and Iman, the Somali-born model who serves as the public face of the De Beers retail chain.

Survival opposes the Botswana government’s resettlement of the Gana and Gwi Bushmen, charging that the government is moving them so it can look for diamonds on their land. The Botswanan government has said the resettlement is intended to improve the Bushmen’s living conditions, and De Beers has denied that diamonds are involved in the resettlement.

According to a Survival press release, “De Beers openly opposes the recognition of indigenous peoples’ rights in Africa, claiming that doing so would lead to ‘apartheid’… Botswana is by far the most important source of De Beers’ diamonds. Since De Beers has refused to change its policy and act to save the Bushmen, Survival has appealed to Somali supermodel Iman to stop using her image to promote the diamond company. In spite of several appeals, she continues to be the public face of De Beers, reportedly being paid around $1 million.”

This is not the first time Survival has targeted Iman and De Beers. In the most memorable instance, the group replaced the model’s face on the De Beers retail chain with a picture of a Bushman. That event was widely blamed for Iman’s non-appearance at the chain’s opening a little while later, though De Beers cited a scheduling conflict. Iman has subsequently appeared at store openings, although press accounts continue to speculate about the fate of her partnership with De Beers.