Detectives investigating the suspected theft of 9,000 euro within a Garda station have narrowed their focus on just a few of their own colleagues.
Just "a handful at most" would have had access to the safe which contained the cash - part of a 26,000 euro haul recovered from a botched shop heist, it has been established.
The money was discovered missing when John Wilson, owner of the Village Store in Lusk, north Co Dublin, asked for it back in mid-February, several weeks after his business was raided.
Senior Garda sources said the cash had been "tagged and tracked" while in the force's possession under normal protocols to protect evidence gathered from a crime scene.
Access to the safe where it was being kept would have been "very limited and very controlled" and the main line of inquiry now was that it was stolen by someone within Garda ranks. Other possibilities that the money, kept in exhibit bags, was mislabelled or misfiled were deemed unlikely after a full search of the Garda station turned up nothing.
A Garda source warned: "The consequences of this will be fairly dramatic. Obviously this has done reputational damage to us and I don't think we could tolerate a member within our ranks that has stolen money."
A detective superintendent from Ballymun Garda station on the city's northside appointed to head up an internal inquiry has been handed a full investigation team while an incident room has been set up.
The Garda Ombudsman said it was not getting involved because no member of the public had made a complaint.
Fears have been raised that any tampering of the evidence could endanger the prosecution of the robbery suspects.
Three armed men threatened staff and customers during the hold up of the Village Store in January before attempting to flee the scene with the money. But gardai intercepted the getaway car and pulled the suspects out of the vehicle.