Russia’s track-and-field federation says it has launched an investigation after several athletes apparently withdrew from a competition to avoid doping tests.
The All-Russia Athletics Federation (ARAF) says it has "established the fact of a mass withdrawal of athletes due to possible doping controls" at one of its Winter Tour events.
The withdrawals came at the Orenburg Mile meet on January 21.
It wasn't clear immediately how many athletes who had entered for races didn't start.
Russia is banned from international track competitions over widespread doping.
It has admitted to doping, but denied there was an organized, state-sponsored program.
Earlier this month, a group of 19 national anti-doping groups called for a ban on Russia’s participation in all international sporting events until it can show it has credible systems in place to prevent doping.