The EU and the US have pushed for Mr Kozulin's release
The former Belarussian opposition leader Alexander Kozulin has left prison and is on his way home to Minsk, his daughter says.
It is not clear whether he has been freed permanently or only so he can attend his father-in-law's funeral.
Mr Kozulin was jailed for five-and-a-half years in 2006 for staging protests against President Alexander Lukashenko.
Mr Lukashenko had defeated Mr Kozulin in an election that international
observers said was severely flawed.
Reports have suggested that Mr Kozulin may have been pardoned.
This month the Social Democratic party stripped Mr Kozulin of the leadership, replacing him with his long-standing rival Anatoly Lenkovich.
Last year he refused President Lukashenko's offer to release him if he left the country.
He was allowed out briefly in February to attend his wife's funeral, but only after a hunger strike that prompted the US and the European Union to push for his release.
Belarus is set for another parliamentary election next month which the president has promised will be free and fair.