THE State has dropped more than half the prosecutions brought against protesters arrested during the historic visit by Queen Elizabeth in May.
More than 20 cases, including allegations of public and violent disorder, have been dropped in recent weeks without explanation, the Irish Independent has learned.
The criminal charges were withdrawn after being reviewed by the Director of Public Prosecutions.
Others were struck out by direction of the trial judge, and in one instance a case was thrown out because the garda witness due to give evidence against the alleged offender was not present in court.
A number of the protesters are now said to be considering suing the State for illegal detention. They claim they fell victim to "kettling" -- a crowd control technique where protesters are corralled by police officers for prolonged periods without being formally arrested -- during the historic visit.
It is alleged a crowd of up to 30 protesters were denied food, water and toilet facilities for up to five hours through "kettling" on the night of the state dinner at Dublin Castle.
No arrests were made on the night.
Last night, Dublin-based human rights lawyer Michael Finucane said that there were significant costs to the taxpayer for the failed prosecutions on top of a €36m policing bill -- for the queen's visit and that of US President Barack Obama -- that had led to a cabinet row over who should pay it.
"There is a cost in the term of the courts' time, administration, garda time and the fact that all of the people who were charged were on free legal aid," said Mr Finucane, son of murdered Belfast lawyer Pat Finucane, adding that many of the protesters had given independent accounts that they were subject to kettling on the night of the state dinner.
He added kettling was illegal in Ireland, saying: "It is effectively a form of detention, there is no halfway between liberty and detention.
"There is no middle ground, you are either free to go or you are under arrest. Otherwise, it is false imprisonment, pure and simple."
The claims of kettling, a technique that is currently being defended by the British Government before the European Court of Human Rights, have been denied by gardai.
"At no stage do we hold persons for hours behind cordons," said a spokesman for the force -- adding that it would be "inappropriate" for the gardai to discuss crowd control measures deployed at Dublin Castle on the night in question for "operational and security reasons".
The massive security operation has already led to a cabinet row over who will pay the €36m garda bill for the Queen Elizabeth/President Obama visits last May, with two government ministers -- Public Spending Minister Brendan Howlin and Justice Minister Alan Shatter-- at odds over who should pay for the visits.