WAR crimes prosecutors want to subpoena supermodel Naomi Campbell to testify over a so-called blood diamond she allegedly received from Liberia's ex-president Charles Taylor.

"Ms Campbell's testimony is necessary as there is evidence that Ms Campbell was given rough diamonds by the accused (Taylor) in September 1997," said a prosecution motion filed with the Special Court for Sierra Leone.

"Ms Campbell's anticipated evidence concerns 'a central issue' in the case: the accused's possession of rough diamonds," states the document, a copy of which was obtained by AFP.

Taylor's war crimes trial heard claims in January that he had given Campbell a "large" diamond after a 1997 dinner hosted by South African ex-president Nelson Mandela.

The diamond was among those Taylor had obtained from Sierra Leone rebels and took to South Africa "to sell .. or exchange them from weapons," prosecutor Brenda Hollis asserted in cross-examining Taylor at the time.

Taylor, on trial since January 2008, denied the claims.

He has pleaded not guilty to 11 counts of war crimes and crimes against humanity stemming from the brutal 1991-2001 civil war in neighbouring Sierra Leone, including charges of murder, rape, conscripting child soldiers, enslavement and pillaging.

Taylor stands accused of having fuelled war in Sierra Leone by arming the rebel Revolutionary United Front (RUF) in exchange for "blood diamonds" - the name given to diamonds mined in rebel-held regions of Africa and sold to fund warfare.

The RUF is blamed for the mutilation of thousands of civilians who had their hands and arms severed in one of the most brutal wars in modern history, which claimed some 120,000 lives.