Marek Migalski, a Polish member of the European Parliament, was denied entry to Belarus in the early hours of May 12, said BelaPAN.
The outspoken critic of Alyaksandr Lukashenka was taken by Belarusian border guards off a Minsk-bound train in Brest and was sent back to Warsaw by another train hours later.
When reached by BelaPAN, Mr. Migalski said that he and two aides had produced tickets to games of the Ice Hockey World Championship to the border guards. Foreigners may enter Belarus without a visa if they have tickets to the tournament's games.
The border guards reportedly told Mr. Migalski that he would not be allowed to enter Belarus because of "Russia's decision." They would not elaborate.
Mr. Migalski's aides were not denied entry to Belarus but decided to travel back to Poland together with the European Parliament member.
Mr. Migalski suggested that Russia could make such a decision in retaliation for his criticism of its human rights record and military intervention in Ukraine.
The MEP had repeatedly called for boycotting this past February's Sochi Olympics and the ongoing world hockey championship in Minsk because of what he described as widespread human rights abuse in Russia and Belarus.
Mr. Migalski planned to hold a news conference in Warsaw on Monday to speak about the incident and urge Poles to visit Belarus during the championship and talk to Belarusians about European values, democracy and human rights.
The politician said that he would not request formal explanations from the Belarusian and Russian authorities over the entry denial.
Earlier this month, Martin Uggla, leader of a Swedish human rights group called Ostgruppen, and Norwegian politicians Emil Andre Erstad and Line Nordhaug were also turned away at the Belarusian border.
