Procedures exist whereby non-EEA nationals may visit the State, subject to their satisfying certain criteria. Those nationals who are subject to a visa requirement must first obtain a visit visa prior to travelling and all persons, whether a visa is required, require leave to land from an immigration officer upon arrival. Generally speaking, persons can be granted up to 90 days permission to enter as a visitor provided they can satisfy an immigration officer that they are a genuine visitor, that they have sufficient funds to support themselves, that they intend to return home following their visit and that they do not intend to breach Irish immigration or other laws during their stay.
The situation described by the Deputy is not specifically addressed in Irish legislation but the basic criteria relating to visits by non-EEA nationals would apply. If the Deputy has a particular case in mind, I would be happy to look into it and advise him further on the matter.