KORONADAL CITY, South Cotabato -- Jail authorities have stepped up security measures at the South Cotabato Rehabilitation and Detention Center after nine inmates tested positive for illegal drug use.

Jail warden Lory Celeste said investigation is now underway to determine the source of illegal drug smuggled into the provincial jail facility.

She said at least 33 jail inmates were subjected to random drug tests recently in which nine of them turned out to be positive for using ‘shabu.’

Jail personnel had earlier conducted operation greyhound of the prison cells which led into the seizure of improvised weapons and illegal drugs which were turned over by the inmates.

Celeste said security measures will be tightened for inmates who go out from the jail facility to attend court hearings.

“We are looking at the possible involvement of the jail guards who serve as security escorts for the inmates in the smuggling of illegal drugs into the prison facility,” the jail warden stressed.

South Cotabato Gov. Reynaldo Tamayo had earlier ordered an investigation into the reported smuggling of illegal drugs inside the provincial jail involving some erring jail personnel.

Tamayo ordered the installation of additional closed-circuit television inside the jail facility and deployed additional jail personnel tasked to monitor the movement and activities of the inmates.