Moscow - Russian race walkers Olga Kaniskina and Sergey Kirdyapkin on Wednesday returned their medals from the London Olympics after their results were annulled for doping, Russia's athletics federation told AFP.
The Court of Arbitration for Sport (CAS) ruled in March to strip six Russian track and field stars -- including the duo and fellow race walker Valery Borchin -- of the titles and medals from a period ranging from 2009 to 2013.
"Kaniskina, Kirdyapkin and Borchin handed their medals to the federation," federation spokeswomen Alla Glushchenko said.
The three other athletes stripped of their titles were race walkers Sergey Bakulin and Vladimir Kanaykin, and Olympic steeplechase champion Yuliya Zaripova.
The Russian athletics federation (ARAF) could not confirm whether these three had also relinquished their medals to international sports bodies.
The decision came after CAS upheld an appeal by the IAAF, which had criticised Russia's "selective" disqualification of these athletes' results, accusing the country of annulling results only for minor competitions.
Kaniskina, who won silver in the 20km event at the 2012 London Olympics, relinquished her Olympic medal as well as her two world champion titles from 2009 and 2011.
Kirdyapkin, who won gold in London, has also lost his Olympic title and his gold medal at the 2011 World Championships.
ARAF also said that Borchin had surrendered his gold medals in the 20km event at the 2009 and 2011 World Championships.
The federation said it would hand the athletes' Olympic medals to the International Olympic Committee (IOC) and the world championship medals to the IAAF.
Russia is now toiling to overturn the provisional suspension of its athletics federation in time for its track and field stars to compete at the Rio Olympics in August.
The federation was suspended in November after a report by a World Anti-Doping Agency (WADA) independent commission that found evidence of state-sponsored doping and mass corruption in Russian athletics.
Russian sports minister Vitaly Mutko said last week that Russia would not include athletes who in the past had committed "gross violations of anti-doping rules" on its Olympic team.
IAAF is set to rule on June 17 whether to lift Russia's provisional suspension.