The Secretary General of the Department of Foreign Affairs has met with the Israeli ambassador in Dublin today over the use of false passports by the alleged killers of a Hamas official in Dubai last month.
Meanwhile, the Foreign Affairs Minister Micheál Martin has described the incident as an "extremely serious one" that puts the security of Irish citizens at risk.
Mahmoud al-Mabhouh was killed last month while staying in a hotel in Dubai by a group of assassins travelling on EU passports
Three of the gang were carrying Irish passports, six had British passports and the others used passports from France and Germany.
Details were provided to the Israeli ambassador in Dublin of the fake passports - and the Israeli authorities have been requested to provide whatever information and assistance they could in this matter.
Mr Martin said they wanted to get answers as quickly as possible - adding that the security of Irish citizens was put at risk.
An inquiry is underway here into how three genuine Irish passport numbers were used in the fake documents.
Two of the passport holders have been notified by the Department of Foreign Affairs, but it is understood the third person has yet to be traced
It was stressed by the Department of Foreign Affairs that, regardless of who was responsible, the Government takes grave exception to the forgery and misuse of Irish passports which could devalue their standing and potentially put at risk the saftey of Irish citizens travelling abroad.