The father of world marathon record holder Kelvin Kiptum has called on the Kenyan government to investigate his son's death - saying four people came "looking for" the athlete days before he died.
The death of the 24-year-old, who won the London Marathon last year, was announced by Kenya's former prime minister, Raila Odinga, on Sunday.
The athlete's coach, Gervais Hakizimana, also died when a car the pair were travelling in crashed on a road between two towns in western Kenya.
Devastated by the death of his only son, Kiptum's father, Samson Cheruiyot, has appealed to the government to conduct an investigation, saying unknown people had been looking for his son days before the fatal collision.
"There are people who came home a while back who were looking for Kiptum but they refused to identify themselves," he told Kenyan news outlet Citizen TV.
"I asked them to provide identification, but they opted to leave. It was a group of four people."
Mr Cheruiyot said he had last spoken to his son on Saturday, when he says the athlete reassured him he was going to win more medals - and that he would become the first person to run an official marathon in less than two hours.
"He told me someone will come and help us build a house. He said that his body is now fit, and he can now run for 1:59," Mr Cheruiyot said.
"Kiptum was my only child. He has left me, his mom, and his kids. I have no other child. His mom was sick for a while. Right now, I'm deeply saddened."
It comes as Kenyan police said the runner died as a result of a traffic accident.
The force said the front part of the Toyota Premio car involved in the crash was intact and that the airbags did not deploy.
"The sensor of the airbag normally is at the front, and if there was no impact on the front part of the vehicle, the airbags will not move," Abdullahi Dahir, Keiyo South police commander, said.
"The impact (on Kiptum's car) was on the roof... on the top of the car... so that's why we could not see the airbags out."
Kiptum achieved the world record for the fastest ever marathon in Chicago in October - crushing the previous mark by 34 seconds with a time of two hours and 35 seconds