The 33-year-old Ugandan marathon runner, who competed in the recent Paris Olympics, had suffered extensive burns after Sunday’s attack.
The authorities in north-west Kenya, where Cheptegei lived and trained, said she was targeted after returning home from church with her two daughters.
Her father, Joseph Cheptegei, said that he had lost a “very supportive” daughter. Fellow Ugandan athlete James Kirwa told the BBC about her generosity and how she had helped out other runners financially.
A report filed by a local administrator alleged the athlete and her ex-partner had been wrangling over a piece of land. Police say an investigation is under way.
Cheptegei, from a region just across the border in Uganda, is said to have bought a plot in Trans Nzoia county and built a house to be near Kenya’s elite athletics training centres.
There are concerns about the increasing cases of violence against female athletes in Kenya. Cheptegei is the third to have been killed since October 2021.
Speaking to journalists outside the hospital where she had been treated, Mr Cheptegei asked the Kenyan government to ensure justice was done after the death of his daughter.
“We have lost our breadwinner,” he added and wondered how her two children, aged 12 and 13, would “proceed with their education.”
Dr Owen Menach, the head of Moi Teaching and Referral Hospital in Eldoret, told local media that the athlete had died after all her organs failed.
Kirwa, who had visited Cheptegei in hospital, told the BBC she “was a very affable person. [She] helped us all even financially and she brought me training shoes when she came back from the Olympics. She was like an older sister to me”.
Uganda’s athletics federation said in a post on X: “We are deeply saddened to announce the passing of our athlete, Rebecca Cheptegei early this morning who tragically fell victim to domestic violence. As a federation, we condemn such acts and call for justice. May her soul rest In Peace.”