PRESIDENT Michael D Higgins has described the revelations of mass graves at the Tuam mother and baby home as "blowing open the locked doors of a hidden Ireland".
He said the discovery was "horrifying" and welcomed the setting up of a commission of inquiry that would "out the truth on record".
Significant quantities of human remains were found at the Co Galway site during recent excavations by the Commission of Investigation into Mother and Baby Homes.
Speaking at Áras an Uachtaráin at a reception to mark International Women's Day yesterday, Mr Higgins said there were "dark shadows that hang over our meeting".
"Shadows that require us all to summon up yet again a light that might dispel the darkness to which so many women and their children were condemned, and the questions left unanswered as we moved on."
Mr Higgins said the work of local historian Catherine Corless, whose research brought the issue to light in 2014, was "another necessary step in blowing open the locked doors of a hidden Ireland".
He added that people have been challenged to consider how the reprehensible attitudes that were held towards so-called "unmarried women" and "illegitimate babies" came to be held.
Meanwhile, a man who was born in the Tuam home has called for all such mother and baby homes to be investigated.
PJ Haverty told RTÉ he lived there with his mother for a year before she was told to leave because "they didn't want this bonding between mother and baby".
Mr Haverty said for years she knocked on the door asking to see her son, but was denied access.
He said the nuns "were supposed to carry out good deeds on this earth and to look after the weak and the vulnerable which they didn't do".
In other developments, Galway County Council said there are no records to suggest human remains were discovered during the construction of a housing estate on the Tuam site.
The authorities have also been urged to carry out tests at a different site in Tuam where the Bon Secours sisters ran a hospital for many years.
The Health Service Executive has secured approval for redevelopment works at the old Grove hospital in the centre of the town.
