ZURICH - Russia's Mariya Savinova-Farnosova has been stripped of her 800m London 2012 Olympic Games gold medal after the Court of Arbitration for Sport on Friday imposed a four-year ban saying there was "clear evidence" she used performance-enhancing drugs.

Russia's Mariya Savinova reacts after she won gold ahead of second placed South Africa's Caster Semenya in the women's 800m final at the London 2012 Olympic Games at the Olympic Stadium, Britain, August 11, 2012.??[Photo/Agencies]

The four-year penalty is retroactive to Aug. 24, 2015, the Swiss-based athletics tribunal said in a statement with Savinova also stripped of her 2011 world championships gold, 2013 world silver and 2010 European gold.

South Africa's double silver medallist Caster Semenya is now in line to be promoted to gold in both the 2012 Olympics and 2011 world championships.

All of Savinova-Farnosova's results between July 26, 2010 and Aug. 19, 2013, are disqualified, with any prizes, medals and prize and appearance money forfeited.

The 31-year-old former 800 metre world and Olympic champion was among athletes that a commission set up by the World Anti-Doping Agency (WADA) recommended be banned for life in 2015.

CAS took the action as the decision-making authority while Russia's athletics federation remains banned over the country's state-backed doping scandal.

Almost the entire track and field team of Russia were banned from competing at the Rio 2016 Olympics.