Plans for apartments on the site of a mother and baby home in County Cork have been rejected by An Bord Pleanála.
The 179 unit development was on privately-owned land on the site at Bessborough and overlaps on an area marked as a potential burial ground.
The board say there are reasonable concerns that the site does contain remains, and believes it would be premature to allow the development to proceed.
The board said: "The Board is not satisfied that the site was not previously used as, and does not contain, a children's burial ground and considers that there are reasonable concerns in relation to the potential for a children's burial ground within the site."
Historian Catherine Corless, whose research unveiled the mass burial of hundreds of children on the grounds of another former mother and baby home in Tuam, has previously said she fears the Bessborough site may be a "carbon copy" of Tuam.
Oral hearings had been held over the plans for the Bessborough site.
Solicitors KOD Lyons described the decision as a "significant victory" for campaigners.
Social Democrats TD Holly Cairns, meanwhile, said An Bord Pleanála had "reached a humane decision" on a sensitive matter.
The Cork TD said: “Given the nature of this site, the unaccounted for remains of hundreds of babies - and the proposed development’s vicinity to the ‘Children’s Burial Ground’ - it was always a highly inappropriate plan."