Foreign affairs minister Micheál Martin is to meet with Israel's foreign minister in Brussels tomorrow in the wake of the controversy over the use of five fake Irish passports by members of a team allegedly responsible for the assassination of a senior Hamas official in Dubai last month.

Martin will be in Brussels to attend meetings of EU foreign ministers and Israel's foreign minister, Avigdor Lieberman, also happens to be in the city on official business, offering the opportunity for talks.

Lieberman will also hold talks with British foreign secretary David Miliband, who has described the use of six fake British passports as an "outrage".

It is understood Martin will outline to Lieberman how seriously the government here is taking the issue.

Dubai's police chief has said he is "99% certain" that Israel's intelligence service, Mossad, was behind the killing. But the Israeli government has said it was "not correct to assume" this was the case.

Israel's ambassador to Ireland was called to a meeting at the Department of Foreign Affairs in Dublin last Thursday but said he "knew nothing" about what had happened in Dubai.

The passports used by the team who allegedly carried out the assassination had genuine numbers but fake names, photographs and signatures.

Foreign affairs officials have already contacted four of the five citizens whose passport numbers corresponded with the fake Irish passports. It is hoped to make contact with the fifth person shortly. All five live in Ireland. None had lost their passport or reported it stolen, and none had travelled to the Middle East. The privacy of the five individuals will be rigorously protected, department sources said, adding that the four contacted so far were "quite shocked" at events.

Three of the five were frequent business flyers and could have been arrested if they had travelled because the passport numbers had been submitted to Interpol.