Last year, Andrzej Poczobut, an ethnic Pole who writes for the Gazeta Wyborcza daily, was given a suspended three-year sentence on charges of libel and insulting President Alexander Lukashenko in his articles. His case had drawn attention to the repressive regime of Alexander Lukashenko, especially from Poland, since Belarus has a large ethnic Polish community.
Poland's Foreign Ministry summoned the Belarusian ambassador on Friday afternoon and presented him with a note of protest over Poczobut's arrest.
Poczobut's wife, Oksana, said he was arrested late Thursday in the western city of Hrodno near the Polish border.
"They threatened, insulted me," she told The Associated Press. "Said they would not leave him alone" until Poczobut stops criticizing Lukashenko.
Belarusian authorities were not available for comment.
Lukashenko has ruled the nation of 10 million for nearly 18 years, earning the nickname in the West of "Europe's last dictator."
The Polish Foreign Ministry noted that Poczobut is an independent journalist as well as the head of a council representing the Polish minority in Belarus, and said his arrest could lead to tighter sanctions against Belarus.
Under Secretary Jerzy Pomianowski, who met with the ambassador, "demanded the immediate release from custody of Andrzej Poczobut," Foreign Ministry spokesman Marcin Bosacki said in a statement. "He noted that such actions deepen the self-isolation of the Belarusian authorities, make relations with the European Union even more difficult, and cause another wave of criticism from international public opinion, which may in turn lead to a tightening of existing sanctions."
The U.S. and the European Union introduced sanctions against Belarus after Lukashenko unleashed a violent crackdown on the opposition after a 2010 vote deemed fraudulent by international observers.
The Organization of Security and Cooperation in Europe also condemned Poczobut's arrest and denounced it as politically motivated.
"I call on the Belarusian authorities to clear Poczobut of the charges and release him immediately. Prosecution of journalists for criticizing the head of state has no place in a modern European country. It chills public debate on issues vital for society," said Dunja Mijatovic, the organization's representative on freedom of the media.
Vanessa Gera in Warsaw contributed to this report.