A relative of General Abacha, and two former ministers who served in his government, have handed over a sum of money reported to total $64m.

The three accused of the theft were involved in a fraud totalling $2.5bn

The money that has now been returned was taken mostly from the national treasury, under the pretence of paying debts owed to a Russian firm for construction of a huge steel plant.

Returned money voluntarily

A government spokesman, Mohammed Haruna, said former ministers Anthony Ani and Bashir Dalhatu, and an unidentified relative of General Abacha, had surrendered the money voluntarily.

A total of at least $800m has now been recovered from officials in General Abacha's government, Mr Haruna said.

He said the international police organisation, Interpol, had been asked to help the Nigerian authorities retrieve the money.

The current Nigerian leader, General Abdulsalami Abubakar, began a crackdown on corruption when he took power after the death of General Abacha last year.