PARIS (AFP) - John Fahey, the president of the World Anti-Doping Agency, has expressed his disquiet at the recent number of positive tests involving Russian athletes.

"I am conscious of the number of doping cases in the past several months that involved Russian athletes, I should add it is a little troubling to see that occur," he told a tele-conference from Canada.

According to Fahey, WADA has spoken to the Russian authorities and offered its help "as it would do for any country".

He added: "No country is immune. We hope that Russia can become more effective with time (in stamping out the problem)."

Last month Russian cross-country skiing Olympic champions Julia Chepalova and Yevgeny Dementiev retired after testing positive for EPO (erythropoietin) at the Tour de Ski at Val di Fiemme, Italy, in January.

Chepalova won gold medals at the Winter Games in 1998, 2002 and 2006. The 32-year-old skier was the world champion in 2001 and 2005 and won the overall World Cup in 2001.

Dementiev, 26, won the gold medal in the 30km men's pursuit at the 2006 Turin Olympics.

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 last December in Ostersund, Sweden.

Russian sports minister Vitaly Mutko has ordered the creation of a special commission to investigate all of the circumstances surrounding the recent doping scandals in a bid to make sure there is no repeat.