Frank McBrearty jnr, who was wrongly convicted over the death of Donegal man Richie Barron, has launched a campaigning group Anti-Corruption Ireland.
He announced the new group at a public meeting held on Saturday afternoon in Dublin's Mansion House. He likened the new group to the One in Four campaign, in that it will seek to deal with what he terms as victims of the abuse of power by State institutions.
Mr McBrearty was accompanied at the launch by eight other speakers on the platform, including TDs Dan Boyle, Joe Higgins and Seán Crowe, as well as journalists Frank Connolly and Eamonn McCann; Aisling Reidy of the Irish Council for Civil Liberties; and Labour Cllr Nicky Kelly and Osgur Breathnach - both of whom were wrongly convicted for the Sallins train robbery in 1976.
About 250 people attended the meeting, including Labour Party justice spokesman Joe Costello.
Mr McBrearty said the primary aim of the group was the setting up of an ombudsman similar to the office of the Police Ombudsman for Northern Ireland, Nuala O'Loan.
"The new Garda Ombudsman that Michael McDowell is setting up does not go far enough," he said, adding "we're calling for an ombudsman that would provide an independent mechanism for accountability so that people with no money know that they can have their complaint fully investigated".
Mr McBrearty emphasised that the initiative was not party political, and "is not left or right, but about human rights".
He said an independent ombudsman would be better than tribunals which he claimed were "a waste of money".
Describing himself as "pro-Garda" yet "pro-accountable policing", Mr Breathnach said that in his and Mr Kelly's case, the only thing that had happened was that gardaí had been promoted.
Subsequently "the State caved in to our cases, refused to defend the gardaí further, but indemnified the costs of the gardaí, with your public money, ad infinitum". He also claimed that he had been recently informed by the Department of Justice "that they have 'active files' on one in five adult males".
Mr Higgins delivered an address in which he asked "who judges the judges?" He retorted: Nobody - there's no redress". He called for "accountable structures for not just gardaí, but for judiciary as well - because that's where things often end up".
His criticisms were backed by Mr Boyle, who said that the judiciary acting as a "self-regulating cartel isn't good enough".
When comments were invited from the floor, the meeting heard a litany of allegations from at least 20 individuals.
Claimants came forward cataloguing allegations from Tipperary, Tyrone, Wicklow, Cork and elsewhere.
Both Mr McCann and Mr Crowe concentrated their criticism on the abuses of power. McCann said: "The politicians are frightened of the guards because the guards know where the bodies are buried."
Ms Reidy said: "The Government knows what needs to be done, but won't do it."
She said the creation of an ombudsman's office should be "a separate institution with a separate Bill - not just a chapter in a Garda Bill".
A new Criminal Justice Bill is being brought in which would extend police powers, including duration of custody, she said.
Mr McBrearty indicated that Anti-Corruption Ireland would be registered as a charity soon and that a large meeting would be held in January. He closed the meeting with a message for Mr McDowell. "I would say this to Michael McDowell; you can't hide what was done to the McBrearty or any other family under the cheque you gave me."