Russian anti-doping agency RUSADA has confirmed that Tatyana Chernova and Yulia Zaripova have both been handed bans for doping offences.
Chernova, who won the heptathlon at the 2011 World Championships, has picked up a two-year ban after taking illegal substances.
Meanwhile, Zaripova has been banned for two years and six months after her biological passport showed abnormalities.
Zaripova claimed gold in the women's 3,000m steeplechase at the London Olympics, but the result has since been annulled and she may lose her medal.
