The president of the Prison Officers Association (POA) has hit out at the volume of what he called "vexatious" complaints being made by inmates against his members.
Stephen Delaney was speaking after new figures provided by Justice Minister Frances Fitzgerald showed that only 5pc of category 'A' complaints made against prisoner officers in the four years between 2012 and the end of 2015 were upheld.
According to the figures provided in a written Dail reply to Socialist Party TD Clare Daly, of the 318 complaints received between 2012 and 2015, only 18 stood up.
The figures show that 247 were not upheld, 30 were incomplete and one was not proved, while 22 were terminated.
Mr Delaney said prisoners making complaints can act with impunity and officers are "left in limbo".
"The figures show the inmates are clearly abusing the system in order to influence prison officers in how they carry out their function by making vexatious complaints," he said.
"The problem for prison officers is that as soon as a prisoner makes a complaint, a full-blown investigation takes place and the prison officer for that period of time is under severe duress and is, quite frankly, in limbo and taken out of the area where the inmate would be."
Mr Delaney said that when a claim is not upheld, "there is no redress for the officer concerned. That is a major problem, and prisoners making complaints can act with impunity".
"Experience has shown that, by and large, the investigative procedure is very professional and as a consequence many complaints are found to be unwarranted," he said.
"The figures show that members are going about their jobs the right way and that there is no question of systematic abuse in any way."
A breakdown of the complaints shows 164 related to "assault", 62 were "racially based", 42 concerned "mistreatment, 26 came under the heading of "sexual" and 24 related to alleged threats and intimidation.
The highest number of complaints - 79 - came from Cloverhill prison. That was followed by Mountjoy (56), Castlerea (37), Midlands (36), Wheatfield (27) and St Patrick's (24) .
Ms Fitzgerald said category 'A' complaints are the most serious level and include allegations of assault and serious intimidation.
She said the Inspector of Prisons has carried out a review of the prisoner complaints procedure and has made a number of recommendations, including one relating to a possible role for an Ombudsman.
"The current complaints system was introduced in the Irish Prison Service in November 2012 based on a model recommended by the Inspector of Prisons who has independent oversight of the process," she said.
"The intention was to have robust procedures in place which would give prisoners access to a credible complaints system that deals with genuine complaints in an open, transparent and independent way."