Belarusian opposition leader Ales Michalevic was arrested Monday at Warsaw airport in Poland, and being detained to "answer further questions," said a spokeswoman for the border police, reported dpa.
Michalevic, who stood against President Aleksandr Lukashenko in elections last year, was granted asylum in the Czech Republic after an arrest warrant was issued for him in his authoritarian native country.
The arrest - apparently based on an Interpol warrant - is embarrassing for the Polish government, one of Lukashenko's staunchest critics.
The Warsaw Foreign Ministry spoke of a "mistake by the state prosecution." Deputy Foreign Minister Krzysztof Stanowski went to the airport in person, to negotiate Michalevic's quick release.