Rebecca Cheptegei, a Ugandan long-distance runner who competed in the women’s marathon at the Paris Olympics before she was severely burned in an attack, died in Kenya on Thursday. She was 33.

She died at the Moi Teaching and Referral Hospital in the city of Eldoret in an intensive care unit, said Dr. Owen Menach, who is on staff at the hospital. The cause was multiple organ failure, he said in a phone interview. The police had said that a man with whom she was in a relationship set her on fire with gasoline on Sunday.

Her kidneys had failed at the time of her hospitalization after sustaining burns to 80 percent of her body, Dr. Menach said.

The Kenyan authorities were investigating the circumstances of her death, Peter Ogwang, Uganda’s state minister for sports, said on social media after her death.

This is a developing story.