Interpol has issued formal notices for the arrest of 11 people wanted in connection with the assassination of a Hamas commander at a hotel in Dubai.
Mahmoud al-Mabhouh was killed by a hit-squad in an operation typical of the Israeli secret service Mossad.
Dubai police say the team used doctored passports of ordinary citizens from Germany, France, Ireland and Britain to conceal their real identities.
In London, the foreign office demanded an explanation from the Israeli ambassador.
The Israeli ambassador to London, Ron Prosor, said: “As you know it is not the usual way to talk about what happened in those kind of meetings.”
Investigators said the identities of three Irish citizens had also been used by the killers. One of them, according to the Irish Foreign Minister, had never been to the Middle East.
The Israeli ambassador to Dublin was also summoned to discuss concerns Ireland has over the safety of its citizens abroad.
Foreign Minister Micheal Martin said: “We do know that two of the three we’ve contacted are regular travellers and indeed one would have been travelling this weekend, and that person could very well have been arrested because of the information that has emerged from Dubai.”
There was a memorial rally for Mabhouh in the Gaza Strip, where Hamas officials vowed never to rest until they reach his killers.
Israel has neither confirmed nor denied that it was Mossad agents who carried out the murder.
Hamas, though, is convinced that Israel either assassinated Mabhouh or had a hand in his killing.