The Department of Foreign Affairs confirmed it has made contact with all six people whose passports were used by the suspects in the killing. It also confirmed none of them had ever travelled to the Middle East.
Despite the security breach, the department said it had no security concerns around pre-2005 passports and there was no need to recall those still in circulation in light of the incident.
The passport numbers used by the suspects are believed to have been from Irish passports issued before 2005. Passports issued after this date have increased security features making forgery more difficult.
“There is no current necessity to recall the pre-2005 passport. This booklet type is a valid passport document, internationally recognised, conforms to international standards and is of a type that is used by many other countries, (although this number is reducing). We are not aware of other recalls of similar type documents in any other country and as is the case in Ireland they are being phased out as they expire naturally,” the statement read.
Hamas commander Mahmoud al-Mabhouh was killed last month in his hotel room in Dubai.
Police in the United Arab Emirates have claimed Israeli intelligence agency Mossad was behind the killing. To date, Israel has refused to confirm or deny its involvement in the incident.
Meanwhile, Australian Prime Minister Kevin Rudd has also expressed his concern that Australian passports were used by some of the suspects in the killing.
Mr Rudd, who described himself as a lifelong supporter of Israel, said he was “deeply concerned” about the killing and would “not be silent on this matter”.
Speaking on radio 3AW in Australia, Mr Rudd said: “Any state that chooses to do this in relation to Australian passports, frankly, is treating the Australian people, the Australian government and the Australian nation with contempt.”
Earlier this week, it was confirmed a vacant property in Ballsbridge in Dublin was given as an address by one of the suspects involved in the killing.
The property is owned by James Reynolds, brother of former taoiseach Albert Reynolds, and father of music promoter John Reynolds.
The family have expressed their shock and said they know nothing about the incident.