A Bank of Ireland worker is being questioned over a suspected inside job in the biggest ever robbery in the country.
The 25-year-old man was arrested on Thursday morning in Dublin over the €7m record heist at the bank's flagship College Green branch last February.
He is being held in Naas garda station in Co Kildare.
The heist was carried out after an armed gang targeted a bank worker, his girlfriend, her mother and six-year-old nephew in a tiger-kidnapping.
An organised crime gang in Dublin was blamed.
Employee Shane Travers, from the north of the city, was forced at gunpoint to drive to work as normal but show a photograph of the kidnap to work colleagues before filling laundry bags with cash from the vaults.
More than one million euro of the stolen cash was recovered in a series of raids on homes and cars across Dublin city about 12 hours after the robbery.
At the time it was likened to the IRA Northern Bank heist in Belfast just before Christmas 2004.
Gardai said the arrested man had been detained on the outskirts of Dublin early on Thursday and was being held under Section 30 of the Offences Against the State Act.
The arrested man can be held for a total of three days.
© Press Association