The man who has reduced murder accused paralympian Oscar Pistorius to tears for the past week teaches children wrestling

Rapport reports in the evenings prosecutor Gerrie Nel teaches tots aged between three and six the finer points of the sport.

The report is accompanied by a blurry photo of Nel in takkies, shorts, and short-sleeved top kneeling on a wrestling mat, talking to two boys.

"He is quiet and modest and completely focused when he trains with the youngsters," the mother of a boy who gets lessons from Nel was quoted as saying.

"He has endless patience and never loses his temper. The children love him," she told the newspaper.

Nel, nicknamed the bulldog, has spend the past week cross examining Pistorius, who is charged with the murder of his girlfriend Reeva Steenkamp.

Nel reduced Pistorius to tears within seconds on Monday by confronting him with the fact that he killed Steenkamp. He has raised his voice at him, used sarcasm, accusing him of lying and tailoring his evidence, and shooting Steenkamp during an argument.

At work Nel is just as focused. He is in the office before 6am and does not socialise with colleagues.

"He is scared of nothing and nobody," an unnamed co-worker told Rapport.

"He is merciless, extremely prepared and focuses on the tiniest detail. Once he smells blood he does not stop."

Nel has prosecuted SA Communist Party leader Chris Hani's killers and former police commissioner Jackie Selebi for corruption. Nel was arrested for corruption during Selebi's case, and spent a night in a Pretoria police station's cells. The charge was dropped a few days later.