IOC chief Jacques Rogge said he was so concerned about the slew of positive doping tests in Russia that he had met Russian President Dmitry Medvedev and demanded action.

Russia has been dogged by drug scandals in recent times with Alena Sidko, one of the country's most experienced nordic skiers, the most recent cheat to be exposed.

She was thrown out of the country's Winter Olympics team last month after testing positive for the banned drug EPO.

"I have been very clear on this, we have indeed been concerned by the number of positive cases," said Rogge.

"I had a meeting with the minister of sport Vitaly Mutko. I alerted him and he said he would do everything in his power to improve the situation.

"I also had a meeting with the president of Russia Mr Medvedev and insisted on strong action on doping. He promised he would launch that and he was very explicit also in public declarations after that."

Rogge, who did not say when he met Medvedev, added that the IOC was working with the World Anti-Doping Agency to clean up the problem.

"We have also addressed this with our partners at WADA. WADA has offered the possibility of the Russian authorities benefitting from a consultancy with the anti-doping authorities.

"So, yes, we have alerted the Russian authorities and we expect them to cooperate."

As well as Sidko, triple Olympic champion Julia Tchepalova and fellow Russian nordic skier Natalia Matveeva were slapped with doping bans by the International Ski Federation (FIS) in December.

Tchepalova is among the most successful women nordic skiers of the past decade, winning Olympic gold in 1998, 2002 and 2006 and claiming world titles in 2001 and 2005.

Another Russian skier, Nina Rysina, tested positive for EPO while competing in France in January.

And in July the International Biathlon Union suspended three Russian athletes for two years for doping violations.

Albina Akhatova, Yekaterina Iourieva and Dmitri Yaroshenko tested positive for EPO during a World Cup event in 2008 in Ostersund, Sweden.

While they are not competing in Vancouver, biathlete Olga Medvedtseva is.

She came second in the women's 15km individual race at the last Olympics in Turin but was disqualified and stripped of her medal for failing a drug test.

Medvedtseva was subsequently banned for two years from all competition, but is now back.

"In law, once you have served your time, you are entitled to enter back into society. What more can I say?" said Rogge.

The Russian city of Sochi is due to host the next Winter Olympics in 2014 and Rogge said the authorities must crackdown on doping.

"I understand people are worried by the number of positive tests, they are legitimate to be worried and the IOC, I believe, has shown its concern by speaking to the Russian president," he said.

"It is up now to the Russian sports authorities to respond."