An Australian filmmaker has vowed never to visit Belarus again after being arrested by the KGB while covering a topless protest against the country's strongman president Alexander Lukashenko.

Kitty Green, 27, was detained during the protest Monday outside the offices of the Belarussian KGB security services to mark Lukashenko's disputed re-election a year ago, reports in Australia said.

Three members of the radical Femen group were also seized by KGB security agents who forced them to strip naked in a forest and threatened to torch them, the group said.

Green had been in the country working on a documentary on the Femen organisation, a feminist group based in Ukraine known for staging protests that frequently see members strip to the waist in public places.

"We can confirm media reports that an Australian journalist was detained in Minsk 19 December 2011, and was subsequently released," the Department of Foreign Affairs and Trade told AFP.

"Consular officials from the Australian Embassy in Moscow provided the journalist with consular assistance."

Green lives in Melbourne and her flatmate Alexandra Shevchenko told the Herald Sun she had now left the country via Lithuania.

"Kitty said she was held in the KGB office and they took her fingerprints and made a file on her. She told me she will never go to Belarus again," Shevchenko said.

"It's a terrible situation. Kitty was lucky and was not hurt like the other girls, but she is from a strong democratic country."

Belarus police had on Monday arrested dozens of regime opponents who tried to stage a banned vigil in Minsk on the anniversary of a brutal crackdown on protests against Lukashenko's re-election.

An AFP correspondent saw plain-clothes security agents grab about 30 men and women holding portraits of political prisoners detained on election night one year ago.

During the Femen protest, one activist impersonated the 57-year-old moustachioed strongman while another brandished a sign in English reading "Freedom to political prisoners".