The lead detective in the Oscar Pistorius investigation has been removed from the case, as he faces attempted murder charges for firing on a minibus full of passengers.

Meanwhile Mr Pistorius' bail hearing has now been adjourned until Friday morning.

Hilton Botha, who took the stand against Mr Pistorius at the Paralympic and Olympic track star's bail hearing earlier this week, is due to appear before a judge in May over the 2011 shooting, police spokesman Brigadier Neville Malila said.

"Botha and two other policemen allegedly tried to stop a minibus taxi with seven people. They fired shots," Mr Malila said.

It was unclear why the charges were reinstated against Mr Botha, or how the latest twist in Mr Pistorius' sensational four-day bail hearing will affect the athlete's chances of securing release from custody pending his trial.

At the time of the taxi bus shooting, Mr Botha, a detective with 24 years on the force, was chasing a man accused of murdering a woman and disposing of her dismembered body down a drain.

The charges against him were provisionally withdrawn but reinstated on 4 February, ten days before the shooting of 29-year-old model and law graduate Reeva Steenkamp in a locked toilet at Pistorius's Pretoria home.

"The decision to reinstate was taken on 4 February, way before the issue of Pistorius came to light or the murder of Reeva was committed," NPA spokesman Medupe Simasiku told Reuters.

"It's completely unrelated to this trial."

Mr Malila said now that the court had decided to charge Mr Botha, there would be an internal disciplinary investigation, which would decide whether to keep him on the case:

He said: "At this stage there are no plans to take him off the Pistorius case."

Mr Pistorius, a double amputee dubbed Blade Runner because of his carbon fibre racing blades, faces life in prison if convicted of the premeditated murder of Ms Steenkamp in the early hours of Valentine's Day.

Sportswear giant Nike froze its contract with Mr Pistorius, saying the athelete should be "afforded due process".

The revelation about Mr Botha capped a troubling 24 hours for South Africa's prosecution service.

Under cross-examination at the bail hearing yesterday, the lead detective was accused of contaminating the crime scene in Pistorius' house and had to backtrack on details, such as the distance of witnesses from the athlete's home.

Grilled by lead defence counsel Barry Roux, he also had to concede that Mr Pistorius' version of events, that he fired into the toilet door in a blind panic thinking an intruder was lurking behind it, was plausible.

The 26-year-old runner denies murder and was more composed in court after repeatedly breaking down in previous hearings.

His uncle, Arnold Pistorius, said his nephew was eating again after consuming nothing for six days and had spent much of his time in police custody reading the Bible.

A full trial is likely to take many months, and even if he is acquitted, Mr Pistorius faces a huge challenge in rebuilding his career and image in the eyes of the millions around the world who saw him as the epitome of triumph over adversity.

The proceedings have gripped South Africans, who have found themselves debating the finer points of police forensics and the ins and outs of the criminal justice process.