A former presidential candidate who fled Belarus in 2011 and accused the authorities of torture was briefly detained upon returning to his country and ordered not to leave the capital.
Ales Mikhalevich, who had received political asylum in the Czech Republic, told RFE/RL by telephone that Belarusian border guards detained him on September 8 when he crossed the border from Lithuania on a train bound for Minsk.
His wife, Milena Mikhalevich, wrote on Facebook several hours later that her husband had been released but was told that he remains under investigation and was ordered not to leave the Belarusian capital.
Mikhalevich, 40, was one of several opposition figures who were arrested and charged with organizing mass riots after challenging authoritarian President Alyaksandr Lukashenka in a 2010 presidential election.
His return poses a challenge for Lukashenka, who is running for a new term in an October 11 election and has freed other opponents who were jailed after the 2010 vote.
Last month, Lukashenka pardoned former candidate Mikalay Statkevich and several other critics who were widely seen as political prisoners, a move apparently aimed at improving his image in the West ahead of the new election.
Mikhalevich told RFE/RL he was returning to Belarus to be with his family, adding that he felt that it was "the right time to come back."
Before his train reached the border, Mikhalevich wrote on Facebook that he had planned to return to Belarus once political prisoners were released. He predicted he would be detained but voiced hope that he would not be held for long.
"I am going to cross the border now. I know that I will be arrested because I remain a main suspect in the criminal case of 'the mass disorders in 2010,' which the investigative committee is reluctant to drop," Mikhalevich wrote.
In English, he wrote: "Hope finally to be with my family and free."
Mikhalevich's wife and two daughters live in Belarus.
Lukashenka has tolerated little dissent since he was first elected president of the former Soviet republic in 1994, becoming a pariah in the West while maintaining very close if often tense ties with Russia. He cracked down hard after the 2010 election.
After his release from custody in 2011, Mikhalevich said he had been tortured at the Belarusian KGB's pretrial detention center and that he refused to cooperate with the authorities.
He then fled to the Czech Republic, where he was granted political asylum. Belarusian prosecutors have put Mikhalevich on the international wanted list as he remained a suspect in the case.
Statkevich was the last 2010 candidate to be pardoned by Lukashenka, who said he was granting clemency "based on the principle of humanism."
Another 2010 candidate, Andrey Sannikau, was sentenced to five years in prison but released in 2012 after a pardon and received political asylum in Britain later that year.
Two other candidates in the 2010 vote received suspended sentences that barred them from politics.
Lukashenka, who has marginalized opponents and muzzled the media during his 21 years in power, is expected to easily win a new term. Western governments and rights groups say elections held under his rule have not been free and fair.