The lawyer Ante Madunic said he was on the phone with Glavas at the time of his arrest late in the afternoon on Tuesday.
"I haven't been officially notified, but I suppose Glavas was detained because the Court of Bosnia-Herzegovina has upheld the verdict by the Croatian court which sentenced Glavas to eight years' imprisonment," Madunic said.
Glavas received the eight-year prison term from the Croatian Supreme Court for war crimes in the eastern Croatian city of Osijek in 1991. He fled to Drinovci, the village where his parents were born, just before the Zagreb County Court handed him a guilty verdict.
According to Madunic, Glavas has three days to lodge an appeal against his detention and 30 days for an appeal against the confirmation of the ruling in Sarajevo.
The spokeswoman for the Court of Bosnia-Herzegovina, Selma Hadzic, could not confirm whether Glavas was arrested or whether the Croatian verdict was confirmed by Bosnia's highest court.
A hearing was held before the court in Sarajevo on September 20 when presiding judge Saban Maksumic said that a ruling in this case would be passed as soon as possible.