People before Profit TD Richard Boyd-Barrett has revealed he may be among those adopted whose births were incorrectly registered.
“I don’t actually know if I am one of the cases involved,’’ he added.
“Probably not, but I have questions now, as do members of my family.’’
Mr Boyd-Barrett was responding in the Dáil on Wednesday to the revelation by Minister for Children Katherine Zappone that 126 people had their adoptive parents incorrectly registered as their birth parents on their birth certificates between 1946 and 1969.
The incorrect registrations were revealed in an analysis of the records of the St Patrick’s Guild adoption society.
Mr Boyd-Barrett had been adopted via the society, adding there were very serious questions for the Sisters of Charity who had overseen the process.
He said thousands more adoptees had very serious questions.
He said 126 people had their identities stolen, adding what was discovered could be the tip of the iceberg.
Taoiseach Leo Varadkar said what happened was another dark chapter in Ireland's history and the matter had to be handled sensitively.
He said there would be a targeted sampling exercise of the other adoption agencies, taking about four months, which would be headed up by Marian Reynolds, former director of social services in Northern Ireland.
When that was completed, there would be a full audit of all the records if that was appropriate, he added.
Mr Varadkar apologised to those affected and denied the Government was stalling legislation which would allow adoptees secure information about their adoptions.
He said the Government was a minority administration and he appealed to the Opposition to facilitate the legislation's passage through the Oireachtas.
Speaking earlier at Government Buildings, Mr Varadkar said: “I think what is going to happen is that we are going to open another dark chapter in our history.
“These are events that happened 50-70 years ago and I know that some people are going to say that what’s in the past should be left in the past and perhaps we shouldn’t open this - this can of worms in many ways. But we have taken a different view as a Government.
“We have now very clear evidence that there were illegal registrations in St Patrick’s Guild and we feel we have to share that information with the people who were affected.
“I think it is far too early to start talking about DNA tests or redress schemes. The sense I have from people that have been affected by this is that they are not looking for money from the taxpayer, they are not looking for retribution.
“They are looking for information about their identities and they want to know who they are and they want to know what their birth stories are and our focus absolutely has to be around that and giving people information that they should have.”
He acknowledged journalists and adoption rights campaigners have been writing about the issue for many years.
“What is different is that the records were transferred over to Tusla in recent years and the analysis of the records has shown documentary evidence of the registrations.”