President Cyril Ramaphosa has appointed Judge Sisi Khampepe to lead a commission of inquiry into whether there were efforts to block investigations and prosecutions of crimes committed during apartheid.

Judge Khampepe will be joined by retired Northern Cape Judge President Frans Diale Kgomo and advocate Andrea Gabriel.

According to the Presidency, the commission was agreed to during a legal settlement with families of apartheid victims who had taken the matter to court.

"For many years, there have been allegations of interference in these cases," said Ramaphosa.

"This alleged interference is seen as the cause of an unacceptable delay in the investigation and prosecution of brutal crimes committed under apartheid. This has caused the families of victims great anguish and frustration."

There have long been claims that political figures interfered in the work of the National Prosecuting Authority (NPA), with even former president Thabo Mbeki being accused. But Mbeki has denied everything.

"During the years I was in government, we never interfered in the work of the NPA. The executive never prevented the prosecutions from pursuing the cases referred to the NPA by the TRC," he said.

"I insist on this despite a 2021 Supreme Court of Appeal judgment which found on the strength of uncontested submissions by former NDPP Vusi Pikoli, that the NPA 'investigations into the TRC were stopped as a result of an executive decision' which amounted to 'interference with the NPA'.

"I repeat, no such interference ever took place. If the investigations Pikoli referred to were stopped, they were stopped by the NPA and not at the behest of the government as alleged by Pikoli. There is no record of a single instance when the NPA stopped investigating and prosecuting any case on account of the so-called 'executive interference', at least not during the period 1999-2008," said Mbeki.

Ramaphosa said the new inquiry will help bring closure and justice to the families of the victims of apartheid.

The commission will also decide whether anyone should receive constitutional damages.

It is expected to complete its work within six months and submit its report within 60 days of finishing.

In a report to parliament in 2022, the NPA said it had handed over 129 apartheid-era cases to the Hawks for investigation.