Last month, Tirop broke the world record in the women-only 10-kilometre road race.
Her career took off when she won the world cross-country title in 2015 at the age of 19, becoming the second-youngest champion ever.
Tirop was found dead at her home in Iten in western Kenya, a town renowned as a training base for distance runners. Kenyan media reported she was found with stab wounds in her abdomen.
"When [police] got in the house, they found Tirop on the bed and there was a pool of blood on the floor," Tom Makori, head of police for the area, said, the BBC reports.
"They saw she had been stabbed in the neck, which led us to believe it was a knife wound, and we believe that is what caused her death," Makori said.
"Her husband is still at large, and preliminary investigations tell us her husband is a suspect because he cannot be found. Police are trying to find her husband so he can explain what happened to Tirop."