The Correctional Services Department has disciplined 64 people and seized gambling equipment in an anti-betting operation.
Department officers conducted 3,000 surprise searches at correctional institutions in the first four months of this year. They seized 31 betting slips and 12 sets of gambling gear.
Sixty-four people were disciplined for participating in gambling or possessing contraband.
The searches were to combat betting in the run-up to the 2016 UEFA European Championship this month.
The department said inmates have been using more inconspicuous materials to make gambling equipment, such as matches issued to them for lighting cigarettes, while items like betting slips were found concealed inside bottles of body powder.
The department will continue the anti-gambling actions during the championship.
