Poland refused permission for a plane carrying Russian Defense Minister Sergei Shoigu to fly through its airspace Friday while attempting to return from a visit to Slovakia, RIA Novosti news agency said.
The agency said the minister's plane turned around and landed back in the Slovak capital Bratislava.
A spokesman for the Polish state air navigation agency said: "It is too early to comment, we are checking all the circumstances that led to this occurrence."
The reason for the reported incident was unclear. Poland has been one of the countries most critical of Russia's actions in the Ukraine crisis, accusing it of aggression against its neighbor.
A Polish foreign ministry spokesman said he had no knowledge of the incident, and a Russian defense ministry spokesman declined to comment.
RIA said its correspondent aboard the Tu-154 plane had been told by a crew member that the pilots had received a message that Poland was not allowing the flight to use its airspace, after which the plane made a sharp turn and flew back.