Minister for Justice Brian Lenihan and the head of the Irish Prison Service, Brian Purcell, have defended the Government's drug-free prisons regime following revelations that inmates have tested positive for drugs 40,000 times since 2005.
However, Opposition parties have attacked the Government's record, saying the report in yesterday's Irish Times was "a wake-up call" for Mr Lenihan.
Labour said the drug-testing results were "shocking", and reflected a prison system which prepared prisoners for a life of crime. Fine Gael said prisons were a "breeding ground for drug addicts".
The figures revealed that 40,000 of almost 100,000 drug tests carried out in jails in 2005, 2006 and 2007 were positive for drugs, including cannabis, cocaine, opiates and amphetamines.
The data, obtained under the Freedom of Information Act, also revealed the number of tests carried out has fallen since the Government's promise in September 2004 of a drug-free prison regime.
In 2005 some 37,288 tests were carried out. This fell to 25,276 in 2006 despite the drug-free regime being formally implemented in May of that year.
The prison service was unable to explain why the number of tests has fallen since the drug-free regime was formally implemented.
Mr Lenihan said a variety of measures had already been put in place to reduce the supply of drugs to prisoners. These include more stringent security checks for staff and visitors. A team of sniffer dogs and handlers announced last July was being put in place "in these weeks".
He was "looking at establishing" a team to gather intelligence on the source of drugs and to search for them in jails. The establishment of that team was also announced by Mr Lenihan last July.
"That's all work in progress. Clearly that progress hasn't impacted in a sufficient way yet to impact on the figures. You'll appreciate that the implementation of these measures cannot be done quickly."
Irish Prison Service director general Brian Purcell said the majority of the tests carried out were targeted at inmates with a known drug-use history. "The figures should not be seen as an indicator of drug misuse across the wider prisoner population."
However, the issue of drug use in prisons was a "significant problem" which he was not trying to "play down".
Labour's spokesman on justice Pat Rabbitte TD said the 40,000 positive tests were reflective of "an abject failure in the Government's drug-free prison policy".
"The finding that 75 per cent of prisoners in Mountjoy tested positive is shocking, and must act as a wake-up call for Justice Minister Brian Lenihan."
He said despite the drug-free regime the prison service had failed to identify the sources of drugs entering the system.
Fine Gael's justice spokesman Charlie Flanagan TD said the Government had made "zero inroads" into prison drug-taking despite promising a drug-free system in 2004. "Incredibly, the level of drug-testing of prisoners has fallen over that period, so the true extent of the current problem is unknown."
