Migrants have since been passed on to the Refugee Applications Commissioner
Five people - including a young child - were discovered in Co Wexford at the weekend, having been stowed away in a lorry from France.
Gardaí found the three men, one woman and minor in Marsh Meadows, New Ross.
They were questioned before being passed on to the Refugee Applications Commissioner.
The migrants, who are reported to be Kurdish, are believed to have travelled on a ferry from Cherbourg to Rosslare on Sunday.