Belarus President Alexander Lukashenko let a midnight deadline pass to intervene in the case of an illiterate Gypsy laborer sentenced to death for the murders of six elderly women.
Vasily Yusepchuk, 30, was thought to be in a Minsk prison early Tuesday, waiting for his unannounced appointment with the executioner, who will dispatch him Soviet-style with a bullet in the back of the head from a silenced pistol.
Lukashenko declined to grant clemency despite pleas from rights activists and European officials, at a time when the authoritarian leader is trying to woo the West to counterbalance Russia's influence.
Belarus is the only country in Europe that still conducts executions, according to Amnesty International.
Under pressure from the West, Belarus has gradually reduced the number of executions, but Lukashenko has resisted calls to abandon capital punishment. Rights activists say more than 400 people have been put to death since Belarus became independent in 1991.
The time and place of the execution is a state secret, and Yusepchuk's family will never be officially told when he died or where his body is buried.
Yusepchuk was convicted in June of robbing and strangling six elderly women. His lawyers say their client was wrongly convicted, claiming the case hinged exclusively on a confession that they claim was obtained through torture.