31/01/2017 14:54 GMT | Updated 02/02/2017 09:06 GMT

Gerrie Nel: I'm Not Leaving The NPA Because I'm Angry

Former top state prosecutor who sent Oscar Pistorius to jail says he left his job because he wanted a new challenge. And he's getting it.

The man nicknamed the "Bulldog" by the legal fraternity says it was not unhappiness that drove him out of the National Prosecuting Authority (NPA) but the need for a new challenge.

Advocate Gerrie Nel sent shockwaves throughout the country on Tuesday when it emerged he had left his job on Monday and would be taking up a position as a private prosecutor.

"I'm not leaving the NPA because I'm upset, I'm creating something new. That for me is why I'm leaving," he told reporters after a press briefing in Centurion on Tuesday.

"It was very difficult for me to resign my position as a prosecutor. I'm a prosecutor at heart. The challenge of creating something and making a difference helped to make that decision," he said.

Wearing a black suit and a white shirt with a back tie, Nel adjusted his glasses as he explained that the new position meant leaving behind a lifetime of memories.

"Yesterday [Monday] was more difficult. When I woke up yesterday I was shocked. I had contemplated being there until I retire and have a big farewell function as a good public servant. It's still difficult. I'm leaving a lifetime behind, a lifetime that I enjoyed, a lifetime that took a lot out of me," he said.

Nel said there were increasing perceptions that there were selective prosecutions, and he'd jumped at the chance to join a new private prosecuting unit at AfriForum, as nobody else was doing this.

AfriForum is a civil society organisation "with the aim of protecting the rights of minorities". In October, AfriForum launched an anti-corruption unit, in cooperation with private investigator Paul O'Sullivan.

The organisation has pushed the narrative of discrimination against white Afrikaners in South Africa, a claim that has been widely rubbished. They have taken footage of farm murders to the United Nations in an effort to get the concept wider recognition.

He has 36 years' experience and was the Gauteng provincial head of the elite crime fighting unit the Scorpions, now known as the Hawks.

He was the man who secured a conviction against disgraced police commissioner Jackie Selebi. His work, however, has made him a target — even within his own unit.

In 2008 Nel was arrested on trumped-up fraud charges while pursuing Selebi, and he spent a night in the police cells. It later emerged that suspended deputy NPA head, Nomgcobo Jiba, was instrumental in securing an arrest warrant against Nel, according to News24.

In 2011 City Press reported that Jiba's hostility against Nel was caused by his involvement in a fraud case against her husband, Booker Nhantsi.

Nel won a murder conviction against Paralympian and Olympian Oscar Pistorius, who killed his girlfriend Reeva Steenkamp on Valentine's Day in 2013. He managed to overturn the verdict of culpable homicide against the athlete, securing a guilty verdict of murder against Pistorius. The Blade Runner served one year in prison after the first conviction, but was sent back to serve six years.

Nel said the support from his family has been valuable and they were fully behind his decision. He vowed that in his new role there would not be selective prosecution. He said there were allegations of selective prosecutions within the NPA and they would be looking into the authenticity of the claims.

"We will look at everything. We want to create an office where there is no selective prosecution. There is a perception of selective prosecutions and if it's correct, we will be right. If that perception is incorrect then I will be unemployed," he said.

Nel said the new unit would start on a clean slate and draft a concept for the type of cases they will be taking. He downplayed criticism that the unit would create the impression of a parallel justice system.

"There is one justice system and I support that. If they [NPA] prosecute a matter then we have no right [to go for the same case]. It's only when they don't prosecute that we will take on the case," said Nel.