A silver medalist at the Beijing Olympics, Anastasia Kapachinskaya, and two other Russian athletes have been banned for four years for doping.
Kapachinskaya, Inga Abitova, and Denis Alekseyev, were caught using the prohibited substance turinabol when their samples from the 2008 Games were retested, the All-Russian Athletics Federation said on June 21.
Kapachinskaya, who also tested positive for stanozolol, was part of the women's 4X400-meter relay team that finished second in Beijing.
Her retested sample from the 2011 World Athletics Championships in Daegu also came back positive.
Abitova took sixth in the women's 10,000-meter race in China while Alekseyev picked up bronze in the men's 4x400-meter relay bronze that year.
The Russian anti-doping agency said the athletes voluntarily admitted to doping violations.
The International Olympic Committee is retesting hundreds of stored samples from the 2008 Beijing and 2012 London Olympics using improved techniques to detect drug cheats.
Russia was accused in a World Anti-Doping Agency report last year of state-sponsored doping. Its athletics team was barred from last summer's Rio Olympics and remains banned.