Pavee Point says it condemns the eviction of 17 families from a Louth halting site.
It is understood they were moved on from Woodland Park in Dundalk, following months of negotiations with the local authority.
Some of the families have returned to the site today as they say they have nowhere else to go.
Martin Collins of Pavee Point says the situation is concerning in light of Ireland's hearing at the UN on children's rights this week.
He said: "Well, the impact on all of the families concerned is going to be huge, the consequences are quite negative.
"First of all, let me say that Pavee Point unreservedly condemn this eviction, it was unnecessary, unwarranted.
"Those families have now been effectively left homeless."