A gun, ammunition and over €150,000 in cash have been seized following the search of a car in Balbriggan.
Gardai stopped and searched a car on Monday evening, and arrested the driver.
The man in his 40s is being questioned at a garda station in Dublin where he can be held for up to three days.
Officers say a number of follow up searches have taken place in the city and further evidence has been recovered.
A garda spokesperson says: "As part of an ongoing regional operation led by the Dublin Crime Response Team to tackle serious criminal activity, Gardaí carried out a planned car stop on the evening of Monday 4th August 2025 in Balbriggan, Co. Dublin.
"On searching the car, Gardaí located and seized a semi-automatic pistol, rounds of ammunition and €153,305 in cash.
"The sole occupant of the car, a man in his 40s, was arrested at the scene and brought to a Garda Station in Dublin where he is currently detained under the provisions of Section 30 of the Offences Against the State Act, 1939 as amended.
"A number of follow-up searches have taken place in Dublin city where further evidence has been recovered."
Assistant Commissioner Cliona Richardson says: "The seizure of this firearm and ammunition has no doubt saved lives, and the removal of significant amounts of cash not only removes ill-gotten gains from the hands from criminals, but deprives them of money they would have used to fund further criminal activity in our communities."
