Minister for Justice Brian Lenihan has said new figures on drug misuse by prison inmates painted 'a very distrubing picture'.
The figures show that detection rates have reached as high as 75% in some prisons.
The data suggests that there has been no reduction in drug consumption in prisons since the launch of the Government's drug free prison policy in 2006.
Mr Lenihan said a number of measures have been introduced since he took office in June 2007, including electronic screening.
He said his department had also increased the number of staff working to help rehabilitate inmates.
The minister also said sniffer dogs would be introduced in coming weeks, and that a dedicated intelligence unit is also due to be established.
Inmates in Ireland's prisons have tested positive for drug use almost 40,000 times over the past three years.
The figures, published in The Irish Times today, were obtained under the Freedom of Information Act.
Inmates have tested positive for a variety of drugs with just short of 34,000 tests showing traces of cannabis use.
Other drugs detected include opiates, cocaine, alcohol and amphetamines.
The data also indicates that the frequency with which drug testing is carried out has fallen.
