Model Naomi Campbell has testified that she was given some "dirty-looking stones" after a 1997 dinner attended by ex-Liberian President Charles Taylor.
Speaking at Mr Taylor's war crimes trial in The Hague, she said late that night, two unidentified men appeared at her room and gave her the stones.
However, she had no proof that the stones were diamonds or came from Mr Taylor, as a fellow guest suggested.
Linking him to illegal "blood diamonds" is key to the prosecution's case.
Mr Taylor is accused of using illegally mined diamonds to secure weapons for Sierra Leone's RUF rebels during the 1991-2001 civil war - a charge he denies.
Prosecutors say that from his seat of power in Liberia, Mr Taylor also trained and commanded the rebels.
The rebels were notoriously brutal, frequently hacking off the hands and legs of civilians.
Ms Campbell, who was late appearing in the courtroom, swore on a Bible before beginning her testimony.
She said that in 1997 she had attended a charity dinner in South Africa hosted by Nelson Mandela at his presidential mansion in Pretoria. BBC News
