The world record holder in the men's marathon, 24-year-old Kenyan Kelvin Kiptum, died in a road accident in his homeland, the BBC reported.
He died along with his coach, Rwandan Gervais Hakizimana, in a car on a road in western Kenya on February 11.
Kiptum made his breakthrough in 2023 as a rival to fellow countryman Eliud Kipchoge - one of the greatest marathoners.
It was in Chicago last October that Kiptum bettered Kipchoge's feat by covering 42km. in two hours and 35 seconds.
The two athletes have been named in Kenya's preliminary marathon team for the Paris Olympics later this year.
Paying tribute to Kiptum, Kenya's sports minister Ababu Namwamba wrote on X: "Devastating sickening!!! Kenya has lost a special jewel. I am speechless".
Kenya's opposition leader and former prime minister Raila Odinga said the country had lost a "true hero" and mourned a "remarkable personality... and an icon of Kenyan athletics".
Sebastian Coe, president of World Athletics, said Kiptum was "an incredible athlete who has left an incredible legacy that will be sorely missed".
The road accident happened on Sunday around 11:00 p.m. local time (8:00 p.m. GMT), the police said, quoted by the AFP news agency.
Giving further details of the crash, police said Kiptum was the driver, and the vehicle "lost control and overturned, killing both on the spot"./BGNES