Supermodel Naomi Campbell will be allowed extra help from a lawyer during her testimony over a "blood diamond" at a Sierra Leone war crimes trial

Prosecutors want Campbell to testify to clarify witness statements that she was given one or more "blood diamonds" - diamonds mined in war zones - by former Liberian president Charles Taylor, on trial in The Hague for war crimes.

Lawyers for Campbell had lodged a request with the Special Court for Sierra Leone for protective measures last week, requesting the court take steps to ensure the fashion model's privacy and safety when she gives testimony on Thursday.

The court ruled it was in the interests of justice to grant Campbell's lawyer a limited right to intervene on whether to allow questions for Campbell if she could incriminate herself by answering them.

In its ruling, the court also said there were "legitimate grounds of concern" for Campbell's security due to the extremely intense media scrutiny of her appearance.

It ordered steps be taken so that "no person shall photograph or video record Ms Campbell while entering the tribunal building, exiting the tribunal building, or while she is in the tribunal building without leave of the trial chamber or Ms Campbell".

Taylor is accused of taking the diamonds to South Africa to buy weapons, which he denies.

In January, prosecutors said that during a visit to South Africa in 1997 Taylor gave Campbell a large rough cut diamond after a dinner hosted by Nelson Mandela.

Taylor denies all 11 charges of instigating murder, rape, mutilation, sexual slavery and conscription of child soldiers during wars in Liberia and Sierra Leone in which more than 250,000 people were killed.