Customs Officers have discovered 56 puppies in a van at Dublin Port.
The van was stopped and searched yesterday in a joint operation between gardaí, Customs Officers and officers from the Dublin Society for the Prevention of Cruelty to Animals.
The puppies have been taken into quarantine.
A 46-year-old man was taken to Store Street Garda Station for questioning.
He has since been released and investigations are ongoing.
Over 30 puppies were found in boxes in the back of two cars stopped by gardai on the Old Malahide Road in Dublin on Wednesday night.
The DSPCA said it believed the animals were being trafficked from puppy farms near the border, and were being taken to Britain to be sold.
The dogs ranged in age from three to eight weeks.