A review carried out by the Central Statistics Office into the quality of garda crime data has found about 18% of crimes reported to gardaí in 2011 do not appear to be recorded on the PULSE computer system.
The review found that about 3% of crimes recorded in PULSE in 2011 have been incorrectly classified to the wrong crime category.
It also found that 7% of incidents classified to Attention and Complaints in 2011 (a non-crime category on PULSE) should have been classified as a crime.
The review was carried out following a Garda Inspectorate report on crime investigation last November, which highlighted systemic failures in recording practices on the garda PULSE system.
The CSO has said its findings are broadly in line with those of the Garda Inspectorate report.
Publication of CSO crime figures was also suspended in the wake of that report.
The CSO is now resuming publication of crime statistics but says that the findings of the review should be taken into account when interpreting the figures.
The CSO has today published crime statistics for the second half of last year, as well as the first quarter of this year.
The figures show that in the 12-month period between March 2014 and March 2015, recorded Assaults and Burglaries both increased by 8.0%. In the same period, groups including Homicide fell by 40.2% while Robbery fell by 6.6%.
Minister for Justice Frances Fitzgerald said: "It is vital that we have access to accurate, reliable data on crime. I expect nothing less.
"Quality data is critical to ensuring that the policing services offered by An Garda Síochána are responsive to emerging and latest crime trends.
"In addition, members of the public must be kept informed and they must be assured that the crime figures they are seeing are accurate," she said.
Fianna Fáil spokesperson on Justice Niall Collins has welcomed the review saying its findings are cause for "serious concern."
He said there is a clear need for extra garda resources.
