An Israeli businessman goes on trial in Geneva on Monday on charges of corruption related to iron ore mining rights in Guinea.

Beny Steinmetz, a former diamond magnate who has already been sentenced in absentia to five years in prison by a court in Romania for money laundering, will appear at the trial in Geneva in person.

Swiss prosecutors say Beny Steinmetz paid millions of dollars in bribes, in part through Swiss bank accounts, to gain the rights to Guinea’s lucrative iron ore deposits – reportedly the largest untapped deposits of iron ore in the world.

The bribes – to Guinean public officials – were allegedly paid with the help of Mamadou Toure, the widow of Guinea’s former President Lansana Conte.

She has been described as the star witness for the prosecution – but her presence in court is unlikely. She now lives in the United States.

Beny Steinmetz will appear and is expected to deny all charges. If convicted, he faces a 10-year jail sentence.