The scutiny process, which proceeds the vote count, follows on from the end of polling in the autonomous Papua New Guinea region's non-binding referendum.
After polling closed on Saturday, officials with the Bougainville Referendum Commission have gathered all 249 ballot boxes at the count centre in Buka.
The Chief Referendum Officer Mauricio Claudio said that as of Sunday afternoon, 103 boxes had been verified, with about 80 officials overseeing the overall process in eight-hour shifts.
