The prisons department found drugs in the possession of an inmate on Thursday after he had received a scheduled visit.
The drugs were confiscated and handed over to the police drug squad for further investigation.
The prisons administration said it had taken a series of measures to combat organised crime and corruption, which appeared to be working.
It added that it was committed to maintain security and order in the prisons and that the guards were implementing the new measures in an exemplary manner.
The administration said efforts were intensive and that smuggling or an attempt to smuggle drugs into the prisons was a criminal offence which carried a prison sentence of up to a year.
