Police in the Republic are investigating an abortion performed on a 12-year-old Irish girl in the UK earlier this year.
Gardai and Tusla, the Irish child and family agency, launched the probe after being alerted about the termination by a clinic because of the girl's age.
It is understood investigators have requested DNA samples from the aborted foetus to confirm the father was a 15-year-old boy - and to rule out the possibility the pregnancy was the result of sexual abuse by an adult.
Child welfare specialist gardai and agency experts are supporting both children and their families as a file is prepared for the Office of the Director of Public Prosecutions, as the age of consent is 17 for both boys and girls under Irish law.
The Garda declined to comment.
Tusla said it did not comment on individual cases to ensure the privacy and protection of the children and families involved, but added: "In cases where a referral is received relating to an underage pregnancy, Tusla's role is to assess and intervene where there are any concerns about the child's safety and welfare, including whether the pregnancy is a result of child abuse.
"It if is suspected or alleged that the child has been abused, Tusla takes immediate protective action to keep the child safe and notifies An Garda Siochana of the suspected abuse."
The referendum on repealing the Republic's eighth amendment, which recognises the equal right to life of the mother and the unborn child, is expected to happen on May 25.
The latest Behaviour and Attitudes poll found almost half of voters, 49%, are in favour of repeal, with 27% opposed. A fifth of voters said they didn't know, while 4% said they would not vote.
Meanwhile, parliamentary questions have revealed that while the UK Government might consider imposing same-sex marriage in Northern Ireland, it would not intervene on the issue of abortion.
Northern Ireland Secretary Karen Bradley said the Government would allow "a free vote on matters of conscience such as equal marriage" and insisted Westminster's power to legislate was "unaffected", despite the matter being devolved to Belfast.
But when asked the same question about abortion, junior minister Shailesh Vara said it was a devolved matter for "locally accountable politicians to consider".
Labour MP Stella Creasy, who led a backbench revolt that forced the Government to allow women from here to access terminations on the NHS in England, claimed debate was being stifled.
She said: "Using devolution as an excuse not to extend equal access to abortion for women in Northern Ireland doesn't wash when the Government have made it clear they are happy to intervene to extend same-sex marriage rights."
But DUP MP Sir Jeffrey Donaldson said any attempt to change the law would "completely undermine the devolution settlement" and pointed out that the Assembly had voted against abortion on the grounds of fatal foetal abnormality in 2016.