Dickson Ndiema was admitted at the Moi Referral Hospital in the western Eldoret city for burns covering 30 per cent of his body.
The hospital spokesperson, Owen Menach, told The Associated Press today that the hospital would issue a statement later but confirmed the patient had died.
Ndiema and Cheptegei were said to have quarrelled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack.
She finished in 44th place.
Cheptegei’s parents said their daughter bought land in the Trans Nzoia county to be near Kenya’s many athletic training centres.
The athlete’s father, Joseph Cheptegei, told reporters last week that Ndiema, his daughter’s former boyfriend, was stalking and threatening her and the family had informed police.
He said he wanted justice and lamented that the suspect was not being guarded at his hospital bed and expressed concern that he might escape.
Cheptegei is expected to be buried at her home in Uganda on Saturday.