Belarusian authorities have briefly detained Alyaksey Shota, the editor in chief of the independent Hrodna.life news portal, in the western city of Hrodna.
In a statement on May 30, police in Hrodna said that the news portal had posted material that was "recognized as extremist."
Shota was later released after questioning.
In March, a court in Hrodna found Shota guilty of disseminating extremist material and imposed a fine.
Shota's detention comes amid a crackdown on independent journalists and opponents of authoritarian leader Alyaksandr Lukashenka.
Belarus dispatched a fighter jet to intercept a Ryanair commercial flight on May 23 and forced it to land in Minsk, where journalist Raman Pratasevich and his girlfriend, Sofia Sapega, a Russian national, were taken off the aircraft and detained.
The plane was flying over Belarus from Athens to the Lithuanian capital, Vilnius.
The move sparked international outrage and demands for Pratasevich's release. The European Union banned flights from Belarus.
Shota had previously worked for Tut.by, the country's largest independent online media outlet.
Earlier in May, police launched a probe of Tut.by, searching the homes of several of its editors and blocking its website.
The Belarusian Association of Journalists said last week that 27 media workers were behind bars, either awaiting trial or serving sentences.
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Big Sentences For Little Protests: Belarus Crackdown Targets Smallest Signs Of Dissent
Belarus has been gripped by nearly unprecedented political turmoil since last August, when Lukashenka declared victory in a disputed presidential election.
Belarusians have taken to the streets around the country to protest. Security forces have arrested more than 30,000 people, including dozens of journalists who covered the rallies.
The crackdown has pushed most of the top opposition figures out of the country.