Supermodel Naomi Campbell has been ordered to testify in the war crimes trial of former Liberian President Charles Taylor about a rough diamond Taylor allegedly gave her in 1997.
The court warned the supermodel that she could be jailed for up to seven years if she refuses to testify.
Prosecutors in The Hague want Campbell to say whether Taylor gave her a rough, or uncut, diamond as a gift during a celebrity-packed 1997 reception in South Africa hosted by then-President Nelson Mandela.
They contend her testimony will support their contention that Taylor lied when he testified that he never possessed rough diamonds.
Prosecutors assert that Taylor dealt in so-called blood diamonds - those mined in a war zone, where the proceeds finance an insurgency.
The Special Court for Sierra Leone issued the order forcing Campbell to testify after she avoided prosecutors for a year and made it known she had no wish to be part of the case.
She was ordered to appear in court in The Hague on July 29 at 9 am "or to show good cause why you cannot comply with this subpoena".
Refusal could lead to prosecution for contempt, which carries a maximum seven-year prison sentence and a fine of 2 million Sierra Leone leones, or about $510, according to the subpoena released by the court.
The appearance of Campbell, as well as of actress Mia Farrow and the model's former agent Carole White, who do not appear to have resisted testifying, will add a touch of glitz to a case already seen as a landmark, the first time a former African head of state has been put on trial by an international court.
The court said the summons will be delivered to Campbell's lawyer in London, Gideon Benaim, who has told the court he will accept it.