Prison officers took an average of over 23 sick days each last year, according to figures released by the Department of Justice yesterday.
The Irish Prison Service lost 75,268 days in sick leave, with officers taking almost three times as many days as workers in the Probation and Welfare Service and more than three times that of workers in the Courts Service.
Minister for Justice Michael McDowell said he was gravely concerned by the figures.
"These figures serve to underscore my absolute determination to reform and modernise work practices and procedures in the Irish Prison Service which, among other things, have given rise to unsustainable and unacceptable levels of overtime working."
Eugene Dennehy, deputy secretary of the Prison Officers Association, said he was disappointed by the Minister's comments. "Prison officers are doing a hugely important job and they need to be supported by the Minister, not vilified.
"The Minister is not comparing like with like when he compares working in the prison service with any other job."
He said the figures should have been broken down to separate leave taken after assault from ordinary sick leave.
A spokesman for the prison service said a review of sick leave was carried out by the Public Accounts Committee. "It found that 15 per cent of all overtime in the prison service is attributed to officers taking sick leave," he said. "If someone is out on sick leave, someone else is called in on overtime to cover them. In 2002 this cost €8.6 million."