The former head of Nelson Mandela's Children's Fund in South Africa has been cleared of charges that he illegally possessed rough diamonds.

A Johannesburg magistrate dismissed charges against Jeremy Ractliffe on Wednesday after hearing several hours of testimony.

Possessing uncut diamonds without a permit is a crime in South Africa because of possible links to funding fighters in African civil wars.

Ractliffe was given the stones by model Naomi Campbell in 1997 as a donation to Mandela's Children's Fund. Campbell said she received them from former Liberian President Charles Taylor, who is on trial for war crimes connected to the trafficking of illegal diamonds.

Ractliffe said he did not tell the charity about the diamonds and held them in a safe for 13 years until handing them over to police.

Ractliffe has insisted that he wanted to protect the reputation of the charity and former president Mandela.

He resigned from the Children's Fund board after the diamond scandal broke.