The Special Criminal Court has been hearing evidence that phone calls were taped at Garda Headquarters, Harcourt Square and 23 divisional garda stations outside Dublin.
Superintendent Michael Flynn from the Garda Telecommunications Unit said the information was stored centrally but could be accessed locally on direction of the Chief Superintendent of any division.
Superintendent Flynn is investigating revelations that telephone calls were recorded at garda stations.
The purpose of his evidence to the Special Criminal Court was to address concerns that calls made by IRA membership suspects to their solicitors while in custody at Cahir and Clonmel last year were taped.
The Superintendent says neither garda station was connected to the garda recording system, which links 23 divisional stations outside Dublin to Garda Headquarters where phone recordings were stored.
He says the 1996 system was digitised in 2008 but that the software programme controlling the recording was switched off at Garda Headquarters last November.
He concedes his investigations are at a very early stage.
The defence are not entirely happy. They have been given until Tuesday to allow a physical inspection of Cahir and Clonmel garda stations.