The head of South Africa's police has appointed a new lead investigator in the murder case of Olympic and Paralympic sprinter Oscar Pistorius, after murder charges against the original officer in the position were reinstated.

Hilton Botha, the officer in question, is facing seven counts of attempted murder along with two other police officers for having opened fire on a minibus containing several people in October 2011, officials said on Thursday. Botha is due to appear in court to face those charges in May.

"We recognise the significance, the importance... and the severity of the matter," police commissioner Mangwashi Phiyega said, announcing that the case had been assigned to a lieutenant general.

The prosecution said that it was unaware of the charges when Botha had been put on the stand at a bail hearing on Thursday to explain why Pistorius should not be given bail.

The third day of Pistorius' bail hearing was adjourned on Thursday without a decision being made on whether he would remain in custody during his trial. The court will reconvene on Friday.

Police Brigadier Neville Malila said that police learned on Wednesday, the same day that Botha appeared in court to oppose Pistorius' bail application, that the charges against Botha and the two others had been reinstated by the Director of Public Prosecutions. The charges had been initially dropped after the shooting incident.

Medupe Simasiku, the spokesman for the prosecutors charging Pistorius with premeditated murder, said he could not say how the charges against Botha would affect their case against Pistorius.

It was clear that they could undermine it, however.

"The [Pistorius] prosecutors were not aware of those charges [against Botha]," Simasiku, of the National Prosecution Agency, said.

Al Jazeera's Tania Page, reporting from outside the courthouse in Pretoria, said the charges against Botha have brought many issues to the forefront.

She said that the developments have "done nothing to bolster the public's confidence" in the police investigation in the case.

Series of police blunders

On Wednesday, the prosecution case against Pistorius began to unravel with revelations of a series of police blunders and Botha's admission that authorities have no evidence challenging the double-amputee Olympic athlete's claim he killed his girlfriend accidentally.

Pistorius faces a charge of premeditated murder, but says he shot girlfriend Reeva Steenkamp accidentally with a licensed firearm after thinking she was an intruder in his house.

In his often confused testimony, Botha, who was described as a 24-year police veteran with 16 years as a detective, conceded that police had left a 9mm bullet from the barrage that killed Steenkamp inside a toilet at the scene.

Police also lost track of illegal ammunition found inside the house, Botha said, and the detective himself walked through the crime scene without wearing protective shoe covers, potentially contaminating the area.

He also claimed in court that police found boxes of testosterone and needles in multiple Paralympic champion Pistorius' bedroom following the Valentine's Day shooting last week, but then said later he was not sure what the exact name of the substance was.

The prosecution conceded laboratory tests on the substance were not yet completed and so it was unclear what it was.

Pistorius' defence solicitor Barry Roux asserted that authorities were taking "every piece of evidence to try to extract the most possibly negative connotation and present it to the court."

The case, which is still only in a bail hearing, has riveted much of the world with its dramatic developments as Pistorius, the man known as the Blade Runner for his famous carbon-fibre running prostheses, says he shot and killed model Steenkamp by mistake.

Pistorius fired four shots through the locked door of a toilet enclosed inside his bathroom because he thought there was an intruder in there, he says.

Prosecutors say he intended to kill the 29-year-old Steenkamp after a fight in the early hours of the morning.