Police said the 57-year-old Vjestica was arrested in his flat in the Bosnian Serb capital under a detention order issued by the Brcko Cantonal Court, but did not specify the charges.
The Public Relations Office of the Republika Srpska Interior Ministry said in a statement Vjestica was arrested under the law on legal assistance and formal cooperation between the Bosnian Serb entity, Bosnia's other entity -- the Croat-Muslim Federation -- and the District of Brcko.
Vjestica was arrested after the Prosecutor's Office of the UN war crimes tribunal in The Hague classified his case "A", permitting that he be tried before a domestic court.