A three-year-old girl was among a group of five suspected Iraqi asylum seekers found in a refrigerated container in a haulage yard.
Immigration officers are understood to have been told they paid 5,000 euro each to be smuggled out of France in near freezing conditions last weekend, the second incident of its kind in the last fortnight.
Gardai said three men aged 20, 23, and 27 and a woman aged 22 - two of whom are believed to be the youngster's mother and father - were found in the container on Sunday.
The cargo of apples had been put on the Irish Ferries' Oscar Wilde service from Cherbourg in western France and taken to Rosslare Europort in Co Wexford.
The unit was picked up by a local haulage firm and driven to a depot about an hour away in New Ross, where the group's shouts raised the alarm at about 6pm on Sunday.
They survived temperatures of just 3C for more than 24 hours.
A Garda spokeswoman said the group was medically assessed in a local station and said to have been in relatively good health.
The 42ft-long (13m) container was classed as "unaccompanied" and is understood to have been locked and sealed. It was taken to the docks in Cherbourg by a freight company and put on the ferry to Ireland where it was collected and transported on by another.
A spokesman for the Irish firm declined to comment.
The container had been packed with up to 26 pallets of apples in the Le Mans-Angers area of western France.
Four adult refugees are believed to have been discovered in a similar container, also carrying apples, in Cherbourg about a fortnight ago.
Brian Killoran, chief executive of the Immigrant Council of Ireland, said: "That those seeking our help during this international crisis are forced to brave a cold container in temperatures as low as three degrees, including a young girl only three years old, is an indictment of how European governments have treated the men, women and children fleeing violence and fear to date."
The group of five suspected Iraqis was initially detained under immigration laws and subsequently their cases were being dealt with by the Office of the Refugee Applications Commissioner in Dublin, a Garda spokeswoman said.
Mr Killoran said the people-smuggling out of France shows the terrible consequences of political inaction and he said it was no coincidence that the latest case happened with the imminent closure of the Jungle camp in Calais.
He said Ireland's commitment to take 21 unaccompanied children this year shows how far we are from a humanitarian response.
Nine refugees were found in a truck on a roadside near New Ross in February this year.
There has been an increased policing operation at Rosslare Port for several months, with more than a dozen immigration officers tasked with checking each ferry that comes in, with local senior officers reporting "numerous" people being deported.