The former head of Nelson Mandela’s Children’s Fund, Jeremy Ratcliffe, has testified before The Hague that the supermodel Naomi Campbell gave him a bag of uncut diamonds while on a train in South Africa in 1997. Mia Farrow, who testifies on Monday, has alleged that Campbell received the diamonds from Liberian President Charles Taylor after a charity dinner hosted by Mandela, at which Taylor was also in attendance. If it is proven that Campbell did receive diamonds from Taylor, it could be a decisive revelation in Taylor’s war-crimes trial: Taylor is accused of using illegally mined diamonds to buy weapons for Sierra Leone’s notoriously brutal RUF rebels during that country’s civil war—rebels that prosecutors say Taylor controlled from his presidency in Liberia. Campbell has said that she received a bag of “dirty-looking stones” in her hotel room from two unidentified men after the dinner. She has also said that she did not have proof that the stones were from Taylor and gave them to Ratcliffe because she thought his charity could use them. For his part, Ratcliffe says he took the stones only because he thought it might be illegal for Campbell to take them out of the country. It turns out that both may have run afoul of South African law, which stipulates that any person without a permit who finds a rough diamond must turn it over to the police, the BBC News reports.