It will be "impossible" for Russia to host formula one and the Winter Olympics in 2014.
That is the claim of International Olympic Committee (IOC) spokesman Andrew Mitchell, who is concerned that the resort city Sochi is also planning its inaugural grand prix in the same region as the next winter games.
"We want to ensure that both events - the Olympic Winter Games and the formula one race - will be staged on the best conditions for all the parties involved," he told Sovetsky Sport newspaper.
"However, we believe that it is impossible to organise two events of such size in one year," added Mitchell.
The media report said the IOC has requested thorough documentation of the F1 project and its construction schedule.
Russia’s Federation of Motor Sports and Tourism vice-president Igor Ermilin said this move is to "understand where and when will be critical moments" of the F1 preparations.
"The IOC wants to make sure that the Olympics won’t fail. That’s why they are worried," he added.