An internal garda committee has expressed concern over the control and management of drugs and cash seized as part of criminal investigations by the force.
The Garda Internal Audit Committee, which is headed by a former senior civil servant, said "close attention" was needed to address the lack of safeguards over the proper recording and handling of vital and often valuable evidence.
The report said the concerns over how gardaí deal with key evidence go back several years and still remain unresolved.
The main role of the committee, which is made up of private sector experts and senior gardaí, is to examine the work done by the Garda's Internal Audit Section (GIAS).
Just over a year ago a previous internal garda report had warned that it was "critical" that gardaí provide adequate additional storage facilities in line with best practice, and that any such systems should be integrated to the Garda Pulse IT system.
The current report, which is an update on the previous year's document, said that there were "23 out of a total of 44 outstanding high priority audit recommendations relating to the control, management and recording of drugs exhibits, property and evidence, including cash held at garda stations".
It went on to say that this was the "highest single category of unresolved audit recommendations" by the end of 2015, the period covered in the latest report.
"While this remains a concern for the Committee, it is noted that An Garda Síochána are addressing this matter as a priority under the Strategic Transformation Agenda."
The report also noted that there were 25 cases of suspected fraud by members of the force or civilian staff, reported to the head of internal audit during 2015.
The number is broadly in line with the same number the previous year. All cases were investigated by 'appointed investigative officers' in line with policy, the document stated.
The committee also said that as a result of staff vacancies, that GIAS had "limited capacity to audit across the garda organisation within a reasonable time-frame".
It said a review of the GIAS staffing showed that four vacancies out of a staffing compliment of ten existed across the professional accountant grades and garda sergeant and executive officer grades.
Staffing has been an issue for the audit team for several years.
However, the committee noted in the latest report that it "can no longer staff two audit teams as was the practice in previous years, thus limiting the capacity to audit across the organisation".