Lobby group AfriForum is giving the National Prosecuting Authority (NPA) until early next year to either prosecute President Jacob Zuma's son Duduzane for culpable homicide or give them the green light to prosecute him privately.

AfriForum CEO Kallie Kriel told journalists that they had given the NPA a January 2018 deadline to release a nolle prosequi certificate (required for a private prosecution), which would allow former NPA pitbull Gerrie Nel to prosecute Duduzane.

"If we have not received any feedback, [we will] go ahead and take the action that needs to be taken," Kriel said.

Kriel added that, according to the law, they need to give the NPA a fair amount of time to make a consideration.

"The act does not prescribe what a fair time is to them," Kriel said, adding that he felt a fair time would be three months.

"According to the law, as soon as you get your nolle prosequi certificate, you only have 90 days to start your private prosecution. Before we come to a point of announcement, like we did today, we need to make sure that we are ready to start prosecution if we get a certificate."

Kriel was speaking during a press conference at the group's head office in Pretoria on Thursday.

In October, AfriForum's private prosecuting unit announced that the first person they would be prosecuting was Duduzane, for culpable homicide in the death of Phumzile Dube, who was killed in February 2014 after Duduzane's Porsche collided with the taxi in which she was travelling.

In August 2015, the NPA decided not to prosecute the president's son after Magistrate Lalitha Chetty found, during a formal judicial inquest into the death, that there was prima facie evidence that Dube's death had been caused by the younger Zuma's negligent actions.

In her judgment at the time, Chetty disclosed that she did not use the standard criminal proof – beyond a reasonable doubt - but that she had applied a less stringent standard.

Dube's family had received only R5 000 from the taxi association and no other compensation.

At the time Nel said AfriForum wanted to make sure all were equal before the law.