A billionaire French-Israeli diamond magnate, Beny Steinmetz, has arrived in court in Switzerland to face trial over alleged corruption linked to a major mining deal in Guinea. He has always denied his company, BSGR, paid multi-million dollar bribes to obtain iron ore mining exploration permits in southern Guinea in 2008. He travelled to Geneva from Israel for the two-week trial. If convicted he could face up to 10 years in prison. Steinmetz, 64, was previously sentenced in absentia to five years in prison by a court in Romania for money laundering. Swiss prosecutors say Steinmetz paid about $10m in bribes, in part through Swiss bank accounts, to gain the rights to Guinea’s iron ore deposits in the Simandou Mountains. The area is believed to contain the world’s largest untapped iron ore deposits. According to the prosecutors, the bribes to Guinean public officials were paid with the help of Mamadie Toure, the widow of Guinea’s former president Lansana Conte. They also allege that Steinmetz forged documents linked to the deal. The BBC’s Imogen Foulkes in Geneva says Ms Toure has been described as the star witness for the prosecution, but her presence in court is unlikely – she now lives in the United States.