JOHANNESBURG (AP) - Forensic scientists on Tuesday exhumed two bodies believed to belong to young activists last seen 24 years ago at the home of Winnie Madikizela-Mandela as police said they have opened a new murder investigation.

The case reopens a dark chapter in the life of the then-wife of Nelson Mandela. Many South Africans still revere the 76-year-old as "the mother of the nation," but others have feared as a vengeful and heartless operator.

She had "the blood of African children on her hands," her former friend Xoliswa Falati told South Africa's Truth and Reconciliation Commission.

In the late 1990s, the Truth and Reconciliation Commission found that Madikizela-Mandela was responsible for the disappearances in November 1988 of 21-year-old Lolo Sono and his friend Sibuniso Tshabalala, 19. But nothing was done to pursue allegations she was directly involved in their killings, even though her chief bodyguard Jerry Richardson told the commission he and a colleague stabbed the young men to death on Madikizela-Mandela's orders.

Mortuary records indicate the two bodies that were unearthed on Tuesday had multiple stab wounds In front of the Truth and Reconciliation Commission, Madikizela-Mandela denied all knowledge of the two and said allegations she was involved in six other killings were rubbish. Madikizela-Mandela could not be reached for comment.

Richardson was head of the Mandela United Football Club, a crowd of young men who acted as Madikizela-Mandela's bodyguards and also as vigilantes who, some charge, she used to get rid of enemies.