Former South African President Nelson Mandela is suing two ex-advisers for allegedly selling copies of his art without permission.
Nelson Mandela's pictures raised money for his Aids charities
Mr Mandela produced a limited edition of sketches and paintings, which were sold to raise money for his charities and to help fight HIV and Aids.
The works included paintings by Mr Mandela of Robben Island, where he spent 18 of his 27 years in prison.
Ex-lawyer Ismail Ayob and associate Ross Calder deny the allegations.
The two men have been asked to provide a full account of earnings and the court is being asked to suspend the sale or marketing of the work until the matter is settled.
They are due to appear in court at the end of the month.
George Bizos, an advocate and long-time friend of Mr Mandela, told AFP news agency that "the stopping of the sale of the works is not negotiable".
Some $4m is unaccounted for, he said.
"We have no idea what monies have accrued and where they have gone."
Mr Bizos said the former president was saddened and upset, not just for himself but for members of the public who may have bought artwork which is not what it seemed.
Mr Mandela strictly defends the use of his name. There are a number of other court cases already proceeding against unauthorised use.
Mr Ayob has portrayed the dispute as being between the Nelson Mandela Foundation - which organises charitable projects on behalf of Mr Mandela - and the Mandela Trust, a private trust fund administered by Mr Mandela's children with Mr Ayob as legal representative.
But the Nelson Mandela Foundation denies the foundation's involvement in the dispute, saying that legal action was being taken in Mr Mandela's private capacity.