The arrestees are members of Qatar's Olympic wrestling team, which was transiting via Moscow to Serbia for the qualifying wrestling tournament ahead of the Athens Olympics.
The Qatar embassy was informed of the incident, noted a source.
The athletes were detained for the failure to declare a big sum of money they were carrying and improperly processed documents.
Russia's Federal Security Service (FSB) has denied to comment on the incident.
However, Russian and foreign experts already qualified the detention as Russia's retaliation to the February 19 arrest in Doha of two Russian security officers. The Qatar officials charged them with involvement in the assassination of ex-Chechen president Zelimkhan Yandarbiyev. Experts predict that Russia will try to exchange the athletes for the Russian nationals, who remain in custody despite Moscow's strong protests.
