The first independent review of a prison smoking ban has found inmates are continuing to make cigarettes from tea leaves soaked in the extract of nicotine patches.
They sometimes then trip the power supply, trying to spark a light, causing power cuts.
The review says the patches have become a valued commodity among prisoners, and the misuse of them is a problem for staff.
Prisons across the country were found to vary considerably in their distribution of patches, with some exchanging an old patch for a new one, others making only lozenges available, and some jail units offering neither.
The Department of Corrections concedes there has been inconsistency in the processses.
It says prisoners are now weaned off patches and lozenges after 12 weeks.