Two Russian biathletes have failed doping tests just nine days before the opening ceremony of the Sochi Olympics, Russian media reported on Wednesday.
The pair are still waiting for the results of their 'B' sample tests.
The International Biathlon Federation (IBU) said it had informed the International Olympic Committee (IOC).
The IBU told Russia's Sport Express newspaper that no case had been opened against the accused sportsmen following their positive "A" samples and that action would only be taken if their "B" samples prove to be positive.
"It is only after these procedures have been undertaken that there can be any talk of definite sanctions and the names of the athletes involved can be released," the spokesperson was quoted as saying.
The Russian Biathlon Union said it could not comment on cases of failed doping tests.
"Until (World Anti-Doping Agency) WADA and the IBU have published their findings, no one has the right to even mention that the sportsmen are under suspicion," a spokesperson said.
(Reporting by Dmitriy Rogovitskiy, Editing by Ed Osmond)