Accident reconstruction expert Kondrad Lotter, who was appointed by late Bosasa CEO Gavin Watson's family to investigate his death, said on Monday he was still waiting for information pertaining to certain aspects of the investigation.
Speaking to News24, Lotter added he was aware of the anticipation for the final autopsy report.
He said the investigation, focusing on the car Watson was driving when he died, had been finalised.
However, Lotter added he was still in the process of gathering information. "At this point, it's a waiting game," he said.
Watson died when the car he was driving, a Toyota Corolla, slammed into a concrete pillar on the way to OR Tambo International Airport.
He was declared dead on the scene.
The moments leading up to his death are still a mystery to South Africans, however, eyewitnesses claim they saw Watson driving at a "massive speed" before they heard a loud crash.
One witness said he saw Watson's car pull over on the side of the road with its hazards on. He then went back onto the road, sped up and later crashed.
"I thought that something was going to happen because he was going straight and the road was making a turn. The next moment, I heard a massive bang," one witness told News24.
"I dropped off my aunt and turned back around again to go back to the scene to see what's going on, and the ambulance was already on the scene," the witness added.
He said, at the time, he suspected the driver had had a heart attack, blacked out, or did it on purpose because the pillar and the bend in the road was hard to miss.
News24 obtained video footage of the wrecked car a day after the crash, which brought about some questions about the integrity of the evidence.
However, national police spokesperson Brigadier Vishnu Naidoo said they were satisfied with the evidence.
"At this stage, we are satisfied that all the evidence required for the purpose of this investigation was gathered at the scene."