The Ombudsman and Information Commissioner is expected to call for an independent complaints body for prisoners today.
Peter Tyndall is expected to urge the Government to bring inmates under his remit at a conference in Dublin today.
Under current rules, those behind bars can only address their complaints to the Irish Prison Service.
The Irish Penal Reform Trust is supporting the move, however executive director Deirdre Malone warned that it must be properly resourced.
"We'd welcome that as a positive and pragmatic step, but of course, like with any mechanism, it depends on having adequate resources, and adequate financial resources and also requisite expertise," she said.
"Prisons are places where people live and work so complaints from within prisons can range from minor things like visiting hours, access to medical treatment, right up to allegations of serious assault."