Eugene de Kock - dubbed 'Prime Evil' for his part in the torture and murder of black South African activists - has been given parole.
De Kock (66) has been in jail for 20 years since he was sentenced to two life terms plus 212 years for atrocities carried out when he was leader of the Vlakplaas police death squad.
The Vlakplaas unit was named after the farm outside Pretoria that served as its headquarters and was the scene of many of its killings.
"In the interest of nation-building and reconciliation I have decided to place Mr De Kock on parole," Correctional Services Minister Michael Masutha said after a hearing on Friday.
He said De Kock had expressed remorse for his crimes and helped authorities find the remains of some of his victims. The date of his release from Pretoria's C-Max High Security Prison will be kept secret.
De Kock confessed to more than 100 acts of murder, torture and fraud when he appeared before the Truth and Reconciliation Commission, which was established in 1995 to consider amnesty for those who admitted to their apartheid-era crimes.
He was given amnesty for most of his offences - including an attack on the ANC offices in London in 1982. The parole decision has been deferred several times over the past year.
Many South Africans believe the death squad leader should die behind bars, but De Kock himself argued that he was the only apartheid figure still being punished for his part in crimes against South Africa's black majority.
"I am the only member of the South African Police Service that is serving a sentence for crimes which I had committed, as part of the National Party's attempt to uphold apartheid and fight the liberation movements," he wrote.
"Not one of the previous generals, or ministers who were in cabinet up to 1990 have been prosecuted at all."
Mr Masutha also announced that Clive Derby-Lewis, a right-wing politician who ordered the 1993 assassination of Communist Party leader Chris Hani, would remain in prison.
Derby-Lewis, who hoped to trigger a race war in South Africa with the killing, is believed to be dying of cancer.
