Senior paramilitary and criminal figures are among up to 800 prisoners and ex-prisoners who are suing the State.
The claimants say they have been traumatised and damaged as a result of being detained in cells that have no flush toilets.
At least 35 prison officers are also taking cases for damages in a class action suit which, like the army deafness claims, could cost the State millions.
Some of the country’s most notorious criminals, among them the Real IRA director of operations, Liam Campbell and the drug dealer, Patrick Holland, are seeking compensation.
The solicitor representing the group, John Devane, says he is taking on new clients at a rate of up to 40 per week.
The Limerick solicitor says he has clients in every prison in the country and still has to visit more prisoners who want to hire him. According to Mr Devane, the inmates have a right to sue the State because their human rights have been violated.
The Department of Justice says it will vigorously contest the claims.
The claims from Irish prisoners follow a Scottish class action where the prisoner was awarded £5,000.
