Naomi Campbell is today due to answer questions in court about whether she was given a blood diamond by a former warlord.
The supermodel is again due to appear unwillingly as a witness at a Special Court for Sierra Leone at The Hague.
Ms Campbell, 40, will give evidence against former Liberian President Charles Taylor who is being tried for war crimes and crimes against humanity.
She has denied Mr Taylor gave her the illegally mined uncut diamond as a gift after a charity dinner hosted by Nelson Mandela in South Africa in 1997. But another guest, the US film star, Mia Farrow, has said otherwise.
Lawyers prosecuting the case say Ms Campbell’s evidence could help link Mr Taylor to the stones, which they say he used to fund weapons in the brutal civil war in Sierra Leone.
Mr Taylor denies the charges and says he has never had anything to do with diamonds.
‘Blood diamonds’ are rough or uncut stones mined illegally, often by children, in areas controlled by rebel armies and used to pay for their violence. The sale of these diamonds is thought to have kept the war going for many years.
Hundreds of thousands of people died in Sierra Leone’s civil war and many were left with horrific injuries. As well as risking their lives in the diamond mines, thousands of children were also forced to fight as soldiers in the war.
Ms Campbell at first refused to appear as a witness at the trial, but she has now been ordered to do so by prosecutors.
The actress Mia Farrow told ABC news that the morning after the party, Ms Campbell told her several of Taylor's men had knocked on her door in the middle of the night and presented her with a rough diamond.
"You don't forget when a girlfriend tells you she received a huge diamond in the middle of the night," Ms Farrow said.
Ms Campbell is said to have donated her diamond to Nelson Mandela Children's Fund, although the BBC reported that the fund told a UK newspaper it had not received any stones from her.
Charles Taylor is standing trial for 11 counts of instigating murder, rape, mutilation and turning children into soldiers. The 62 year old has pleaded not guilty to all 11 charges at the UN-backed tribunal. He is also accused of buying weapons for Sierra Leone's rebels, who were notorious for hacking off ordinary people’s hands and legs during the 1991-2001 civil war.