Fine Gael has called for an investigation into why two-thirds of the 360,000 cases that appear before the Distict Court annually result in no penalty being imposed.
Figures released today in the Courts Service annual report also show that nearly half of all cases in Dublin are struck out without any court hearing at all.
Fine Gael TD, Mr John Deasy today called for an inquiry by the Minister for Justice, Equality and Law Reform, Mr McDowell.
"The Minister for Justice must urgently investigate why our criminal justice system is not functionally efficiently and effectively," said Mr Deasy.
"These statistics will do nothing to help public confidence or aid the determination of gardaí to pursue cases. Political responsibility for this rests with the Government which is now in its seventh year in office," said the Waterford TD.
"These figures are extremely worrying and require urgent inquiry. While it would be wrong to expect anything near a 100 per cent success rate in all cases, it is disturbing that only 34 in every 100 offences dealt with results in a penalty being imposed.
"This failure rate suggests substantial wastage or misuse in the resources deployed by the gardaí, the DPP and the Courts Service. We must find the answer to why almost one in every two cases Dublin District Court cases are struck out," he said.