Doctors treating Nelson Mandela have been forced to deny a claim he is in a "permanent vegetative state" that was made in court papers by a lawyer representing close members of his family.
The document, published yesterday, also suggested that 94-year-old Mandela's relatives had been advised by doctors to switch off his life-support machine.
Medics treating the former South African President, who is entering his fourth week in hospital, said the family should consider letting him go rather than "prolonging his suffering", the document added.
It was leaked as members of Mandela's large family engaged in a war of words over his legacy - and were called on by his former ally, Archbishop Desmond Tutu, not to "besmirch" his name.
"Please, please, please may we think not only of ourselves. It's almost like spitting in Madiba's face," Tutu said in a statement yesterday.
The document, which offered the bleakest picture yet of Mandela's fading health, was submitted to a closed hearing last week by a lawyer acting for Mandela's oldest daughter Makaziwe during a court battle with his oldest grandson Mandla.
Dated June 26, it was leaked to the AFP news agency yesterday.
"He is in a permanent vegetative state and is assisted in breathing by a life support machine," it read.
"The Mandela family have been advised by the medical practitioners that his life-support machine should be switched off. Rather than prolonging his suffering, the Mandela family is exploring this option as a very real probability."
Yesterday, Jacob Zuma, the South African President, issued a "clarification" in which he said that Mr Mandela's doctors denied his situation was a bleak as suggested.
"Former President Mandela has been and remains under the care of a multidisciplinary panel of South African medical experts drawn from the South Africa Military Health Services, the public sector, the universities and the private sector.
"Under this panel a team of doctors, nurses, paramedics and other health professionals attend to Madiba on a 24-hour basis."
A government statement said: "We confirm our earlier statement released this afternoon after President Jacob Zuma visited Madiba in hospital that Madiba remains in a critical, but stable condition. The doctors deny that the former President is in a vegetative state."
Mandela is now entering his fourth week in hospital in Pretoria where he was admitted for a recurring lung infection and is now on a ventilator.
Graca Machel, his wife, spoke publicly for the first time about her husband yesterday, insisting he was "fine" and not in excessive pain. "Although Madiba sometimes may be uncomfortable, very few times he is in pain, but he is fine."
Mac Maharaj, Zuma's spokesman, questioned whether Mandela's condition had been exaggerated by lawyers acting for the family in the court case. "We have reported even today as a result of President Zuma's visit that Madiba remains in a critical but stable condition and that is based on Mr Zuma going to the hospital and being briefed by the doctors. Certainly in that statement, there is no suggestion that he is in a vegetative state."
The claims about Mandela's health emerged in a statement entitled "Certificate of Urgency" submitted to a high court close to the former president's childhood home in Qunu, in the Eastern Cape. The court has been hearing arguments in a dispute over where several of Mandela's late children should be buried - the key issue of a bitter family feud - and the certificate was part of an argument for the case to be expedited.
On Thursday, the court ruled that the remains of three of the former statesman's children should be immediately exhumed and reburied in a hillside plot close to where Mandela is expected to be buried when he dies.
Makaziwe Mandela, backed by Machel and most of the Mandela family, took Mandla Mandela to court after he dug up the bodies from Qunu two years ago and moved them to the nearby village of Mvezo, where he is a chief, and has built a visitor centre. Yesterday, having disinterred the remains from Mvezo, Mandela's family are thought to have reburied them in the grounds of his Qunu home.
Tutu appealed to the family to reconcile in his memory. "Your anguish, now, is the nation's anguish - and the world's. We want to embrace you, to support you, to shine our love for Madiba through you," he said. "Please may we not besmirch his name."