Russia's Olympic Committee have said that eight of its athletes from three different sports had tested positive for banned substances in a re-examination of samples taken during the 2012 London Olympics.
Russia's track and field athletes have been suspended since November due to suspicions of a systematic doping program and the latest positive tests are a major blow to the country's hopes of sending a full team to the Rio Olympics in August.
Doping scandals have plagued the build-up to this year's Games in Brazil.
Earlier this week, the ROC said 14 of its athletes from the 2008 Beijing Olympics had tested positive for banned substances.
And on Friday, the International Olympic Committee said 23 athletes from five sports at London 2012 had tested positive for doping during re-checks.
Russia is under investigation following a report by the World Anti-Doping Agency that suggested a widespread doping program.
The ROC said on Saturday it would not name the athletes with the latest positive tests until they had the results of their B-sample tests and following the start of official disciplinary proceedings.
That is expected to be early next month.
In a bid to improve its chances of returning to competition in time for Rio, Russia's athletics federation has said it will not include any athletes on its Olympic team who had been banned for doping in the past.
Reuters
