Two-thirds of the 360,000 cases that appear before the District Court annually result in no penalty of any kind being imposed, Fine Gael TD Mr John Deasy said yesterday.
He called for an inquiry by the Minister for Justice, Equality and Law Reform, Mr McDowell, into the figures.
"The Minister for Justice must urgently investigate why our criminal justice system is not functionally efficiently and effectively," said Mr Deasy, who said that one in every two cases are struck out without any hearing taking place.
"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."
"We must find the answer to why almost one in every two Dublin District Court cases are struck out," he added.