Lyabedzka told Reuters by telephone that he had been taken in for questioning in Mahilyou, a town in eastern Belarus, on allegations of staging an illegal rally.
He said he was meeting voters in the street since local authorities refused to give the group a hall. He said between 200 and 250 people attended the meeting.
Lyabedzka said that after the meeting, police came up and ordered him to go to the station where he was accused of holding an illegal rally.
Lyabedzka's spokeswoman, Katsyaryna Tkachenka, later said a court had imposed a fine equivalent to $700 and released him.
Belarus Votes 2006
MEET THE CANDIDATES: Read brief biographies of the four candidates in the March 19 election.