A committee of the European Parliament has said it will visit the medieval Carrickmines Castle site in south Dublin.
The Committee is to assess if the €75 million of EU funding ear-marked for the completion of the M50 motorway should be suspended.
The Committee's decision to travel to the controversial site follows an invitation by Labour MEP, Proinsias De Rossa, who has complained that the Irish Government is failing to protect a unique piece of archaeology.
In a submission to the Committee, Mr De Rossa included documentation which shows concerns were raised in 1997 about the 'inadequacy' of the draft Environmental Impact Study for the motorway.
Meanwhile, the European Commission has told Mr de Rossa that if the Irish authorities are found to have broken EU laws relating to the protection of archaeological sites, grant aid for the motorway could be withdrawn.
It has also agreed to raise the issue with the Minster for Transport, Séamus Brennan, when they meet him on the taxi deregulation issue.
The Minister for Transport, Seamus Brennan, has said the M50 motorway has to be completed in line with current plans.
Dun Laoghaire-Rathdown Council and the National Roads Authority have repeatedly stated that all statutory regulations in relation to the M50 were fully complied with and that millions of euro have been spent on archaeological investigations.
The issue is due to return to the High Court following a successful Supreme Court hearing by protestors intent on keeping the castle remains intact.
