Revenue officers have seized over 65,000 unstamped cigarettes and €1,530 in cash as part of an intelligence-led operation in Cork city.
A search was carried out under warrant at a house in the city on Thursday.
The cigarettes, branded 'Minsk', 'Marlboro' and 'NZ', were found with the help of detector dog Eva.
They had a combined retail value of over €39,000 - representing a loss to the Exchequer of around €31,000.
Officers also seized €1,530 cash, suspecting it to be the proceeds of, or intended for use in criminal activity.
A Lithuanian man aged in his 30s was questioned.
Revenue officers were given a three month cash detention order to allow for further investigations to be carried out by Judge Patricia Harney at Cork District Court on Friday.
Investigations are ongoing with a view to prosecution.