Former Olympic rhythmic gymnastics champion Natalia Lavrova died in a car accident on Friday, the Russian Rhythmic Gymnastics Federation said.
Lavrova, 25, was riding in a car involved in a collision near the city of Penza, southeast of Moscow, a Penza province traffic police official said on state-run Rossiya-24 television.
Rossiya-24 said Lavrova's sister, who was driving, was also killed.
Lavrova won gold in the rhythmic gymnastics team event at the 2000 and 2004 Olympics.
"Her tragic death is a huge, irrecoverable loss," the federation said on its website.
The website said she had been head coach of the Dinamo club and coach with an Olympic training centre.
Lavrova was "a magnificent coach and a magnificent gymnast," Alina Kabayeva, a 2004 gold medallist who is now in Russia's parliament, said on Rossiya-24.