The Times has reliably established that police officers at the scene of the accident - in which four women and a man were killed - failed to draw blood from driver Sibusiso Langa within the prescribed two hours.

At least two sources close to the investigation have confirmed that Langa's blood was drawn about four hours after the accident, which was at the intersection of Olifantsfontein and Lever roads, in Midrand, on October 22.

The delay, they say, was partly due to confusion about in whose jurisdiction the crash took place. It occurred halfway between Johannesburg and Pretoria.

There was also confusion about where the motorist should be taken for his blood to be drawn.

Though statements by witnesses at the scene are yet to be finalised, officials said the "mess" by the officers would not only affect the prosecution but would also further traumatise the dead runners' families.

One official, speaking on condition of anonymity, said: "This is not good. With so many deceased, one would have expected the police to be extra cautious and follow the law to the letter. Tests conducted as prescribed by law are a gem for the prosecuting team."

Earlier, reports alleged that Langa had tried to walk away from the carnage and that he was so drunk he had to be reminded that he had driven into the joggers.

Langa, 43, a mechanical engineer, faces five charges of murder, one of attempted murder and another of drunk-driving.

He allegedly ploughed into the runners after losing control of his Mercedes-Benz ML500.

Moroese Mokoatsi, 34, Reneilwe Lesenyeho, 31, Given Mills, 30, Isaac Tlale, 37, and Nomvula Dumako, 35, were killed in the crash. They were all buried at the weekend.

The only survivor, Khanyiswa Stengile, was admitted to Fourways Life Hospital and underwent extensive surgery.

Another official alleged that, though it was certain that Langa's blood test would show an alcohol level above the legal limit - he was allegedly "very dronk " - investigators were engaged in extensive "damage control" to firm up the prosecution's case.

"There is no doubt that he was very dronk; it's just a case of how much over the limit he was. He will not escape this," the official said.

A Justice Department insider said that, though there could be repercussions about the delayed tests, all was not lost because there was other evidence, including statements by witnesses and paramedics at the scene of the accident.

"We have prosecuted many drunk-driving cases, some very similar. The court has in the past accepted witnesses' statements as evidence," said the Justice official.

A relative of one of the slain runners, who wanted to be identified only as Pinkie, said it would be a travesty if Langa's blood had not been drawn until four hours after the crash.

"That would be negligent, especially if it will have a negative impact on the case," she said.

Pinkie said the families were still battling to come to terms with their loss and the purported bungling was a further setback.

Private forensic consultant David Klatzow said such a bungle would put the state in a "very difficult" position.

"It's beyond belief that they would stuff-up like that. The blood test has to be administered at [most] two hours from the last time of driving in order to create a presumption."

But Klatzow agreed that all was not lost because, from reports on the incident, Langa appeared to have been "substantially drunk".

He said that though the two-hour timeframe was crucial to blood-alcohol testing, the body metabolised alcohol at a rate of 10% every hour.

Langa was on Friday granted R80000 bail. He will reappear in court on November 25.

As part of his bail conditions, Langa, who also holds US citizenship, had to surrender his passports and his driver's licence.

The National Prosecuting Authority was unable to respond to questions at the time of going to press.