MOSCOW, November 13 (RIA Novosti) - The decision of The Court of Arbitration for Sport to uphold bans on biathletes Albina Akhatova and Yekaterina Iourieva is a blow to Russia's Winter Olympics hopes, a top sports official said on Friday.

The bans were originally imposed on August 11 after Akhatova and Iourieva tested positive for the banned endurance-boosting hormone EPO last December.

The bans for Akhatova, a five-time Olympic medalist, and Iourieva, a former world champion, run until December 2010, meaning they will miss the Vancouver Games.

"This is a huge loss for the team," Alexander Tikhonov, the first vice president of the Russian Biathlon Union, told RIA Novosti. "It is a real pity... we have lost two biathletes who had a real chance of winning Olympic medals."

Under IOC rules, the pair will also miss the 2014 Winter Olympics, to be held in Russia's Black Sea resort of Sochi.