Seizures of illegal drugs in Mountjoy Prison would suggest that heroin and cannabis are the most commonly used substances. For obvious reasons it is not possible to quantify the total volume of illegal drugs being brought into or consumed in Mountjoy Prison. I can say, however, that the improved security and related measures which I have introduced over the last three years have been successful in significantly curbing the smuggling in and use of illegal substances within the prison. This is reflected in the significant increase in the number of drug seizures made there. The number of seizures in the main Mountjoy Prison involving illegal drugs and drug paraphernalia which resulted in formal prison disciplinary proceedings against prisoners over the last three years which were as follows: 1924 — 172; 1995 — 392; 1996 — 423.