Three more Russian competitors have been dropped from the country's Olympics team over drugs tests.
Walkers Valery Borchin and Vladimir Kanaikin tested positive for the banned substance EPO, their coach Viktor Chegin said.
Cyclist Vladimir Gusev has also been dropped after a disputed drugs test showed abnormal blood values, although he did not test positive for doping.
Last week, seven track and field athletes were provisionally banned.
Chegin said Kanaikin - a former world record holder - and Borchin tested positive for EPO in out-of-competition tests in April.
A third walker, Alexei Voevodin, who had not been selected to go to Beijing, also failed a drugs test.
Gusev spent a lot of time at altitude and his body was attuned to elevation where there is less oxygen. That alone has the effect of changing blood indicators
Head of Russian Cycling Federation
It is the latest in a string of doping scandals to hit the Russian Olympics squad.
Gusev was set to compete in the individual time trial on 13 August and had been tipped to win a medal.
But he was fired by his Astana team in July after internal tests showed he had abnormal blood values.
Russian Cycling Federation chief Alexander Gusyatnikov suggested that Gusev's high-mountain training for Beijing could have altered his blood values.
He said: "This is a tragedy for the athlete, this kind of suspicion.
"Gusev spent a lot of time at altitude and his body was attuned to elevation where there is less oxygen.
"That alone has the effect of changing blood indicators. But all we can do now is wait and follow procedures."
Gusev's place in the team will be taken by Denis Menchov who finished fourth in this year's Tour de France.
Seven track and field athletes were provisionally banned last week by the sport's governing body, the International Association of Athletics Federations (IAAF) on suspicion of manipulating their out-of-competition urine samples.
Russian Sports Minister Vitaly Mutko called those bans unprecedented, but said avoiding scandal was more important than losing medals.