This followed the release of a World Anti-Doping Agency (Wada) report at the end of 2015 which recommended Savinova receive a "lifetime ban from sport".
Wada released its findings into allegations made in a documentary on German TV channel ARD in December 2014 of systematic doping in track-and-field events particularly in Russian athletics.
“On the basis of clear evidence, including the evidence derived from her biological passport, Mariya Savinova-Farnosova is found to have been engaged in using doping from July 26 2010 through to August 19 2013,” CAS said in its ruling.
“A four-year period of ineligibility, beginning on August 24, 2015, has been imposed on Mariya Savinova-Farnosova and all results achieved by her between July 26, 2010 and August 19, 2013, are disqualified and any prizes, medals, prize and appearance money forfeited.”
The CAS acted as first instance decision-making authority in the arbitration between the IAAF, the Russian Athletics Federation (RusAF) and Savinova, substituting for RusAF, which was suspended at the time the matter was ready to be adjudicated.
Savinova was identified in secret recordings in the documentary where she admitted to taking banned substances.
Speaking shortly after the Wada report was released, Semenya said earning the gold in this way would almost be an empty victory.
“I ran the Olympics and I won the silver medal, so I can’t celebrate anything other than my silver even if they crown me Olympic champion it is just an award from them I never celebrated,” Semenya said.
“It wouldn’t mean anything for me, it would be great for my country but for me as an athlete I cannot entertain the thought.”
Semenya could become the first female back-to-back Olympic 800m gold medallist and first women to win the double in the two-lap race at the Games.
The IAAF yesterday said Savinova had 45 days to appeal the decision which could drag out the process with Semenya having to stay content with her two silver medals.
The Pretoria News