The Democratic Alliance on Thursday raised concerns about the process and fairness of the decision to turn down the parole application of apartheid-era assassin Eugene de Kock.
"It seems that the process was not followed fully," said DA MP James Selfe in a statement.
On Thursday, Justice and Correctional Services Minister Michael Masutha announced that De Kock would have to wait another year before his application for parole was reconsidered -- in order to allow the families of his victims to be consulted.
"I have not approved parole at this stage but have directed that a further profile be re-submitted not later than 12 months from today instead of the two-year period prescribed by the law," said Masutha.
Selfe said that, besides De Kock, there were many other apartheid officials who had sanctioned the crimes De Kock committed but who had never been held accountable for their actions.
"It seems somewhat inequitable that Mr de Kock, who committed extremely serious crimes as a functionary of a thoroughly evil system, is seemingly the only one punished."
De Kock was in charge of a police "death squad" at Vlakplaas, outside Pretoria, and was arrested in mid-1994. He was convicted and sentenced in the High Court in Pretoria in 1996.
He was sentenced to two terms of life imprisonment for six murders and to a further 212 years' imprisonment on charges including conspiracy to commit murder, culpable homicide, kidnapping, assault, and fraud.
Now aged 65, De Kock has served 18 years in prison.