The minister said morally and legally the killer should be freed
A black member of a police hit-squad in apartheid South Africa, who confessed to killing eight ANC members during the 1980s, has been granted parole.
The correctional services minister, herself a former operative in the ANC's armed wing, said the decision came after consulting the victims' families.
Even so she said it "was a difficult one to swallow".
Almond Nofemela was pardoned in the reconciliation process, but was serving life for the murder of a farmer.
After seeing Nofemela on Monday, Correctional Services Minister Nosiviwe Mapisa-Nqakula said she was also told by prison officials that the former apartheid hit-squad operative had been a model prisoner.
He participated in community outreach programmes and regularly spoke to groups of youngsters about the dangers of crime, HIV/Aids and drugs.
She said both morally and legally, Nofemela should be reunited with his family
The minister added that she expected South Africans to appreciate the spirit of the decision.
"All of us recognise there was a struggle. Many people lost their lives," she said.
"But this is a time for nation-building. We cannot be looking back."
The BBC's Mohammed Allie in Cape Town says Nofemela was sentenced to death in 1987 for the murder of a farmer at a time when capital punishment was still on the statute books.
He avoided the gallows by spilling the beans on the eve of his scheduled execution about the activities of the notorious death squads operated by apartheid security forces, our reporter says.
He confessed to killing eight ANC members including well-known human rights lawyer Griffiths Mxenge and Zwelibanzi Nyanda, brother of the country's Communications Minister Siphiwe Nyanda.
Although he was pardoned by the Truth and Reconciliation Commission for making a full disclosure, Nofemela had his death sentence converted to life imprisonment for murdering the farmer.
Responding to the release of his brother's killer, Mr Nyanda said he held no bitterness or animosity.
However, a spokesperson for the Mxenge family says while they respect the decision, they were disappointed with the parole and had expected Nofemela "to rot in jail".