Germany joined France, Britain, and Ireland on Thursday in demanding Israel to provide any information it had which might help explain the circumstances surrounding the death of a top Hamas official in Dubai.
The request was made by the Foreign Ministry's Middle East envoy, Andreas Michaelis, during a meeting with Emmanuel Nahshon, counselor at the Israeli embassy in Berlin.
The meeting came after authorities in Dubai said they were nearly certain Israel's intelligence agency, Mossad, was behind the death of Mahmoud al-Mabhouh in a luxury hotel in the city-state on January 20. One French and one German passport were used by the suspected assailants.
"In view of the information available so far, I believe it is imperative to explain the circumstances surrounding the death of Mahmoud al-Mabhouh, German Foreign Minister Guido Westerwelle said.
"Germany will do everything it can to contribute to resolving the matter," he added.
Germany's announcement came after France asked earlier that Israel explain how a forged French passport came to be used by the alleged assassins.
"We are asking for explanations from Israel's embassy in France over the circumstances of the use of a fake French passport in the assassination of a Hamas member in Dubai," the Foreign Ministry said in an electronic news briefing.
Meanwhile, the web of countries allegedly involved in the January assassination of Hamas strongman Mahmoud al-Mabhouh continues to grow as the Wall Street Journal reported Thursday that Dubai authorities are looking into five U.S.-issued credit card accounts suspected to have been used by the alleged assassins.
The cards, according to the Wall Street Journal report, issued by U.S. banks, were used by the suspected assassins to buy plane tickets connected to the operation, as well as other travel related items.
Earlier Thursday, British Foreign Secretary David Miliband demanded Israel's full cooperation in investigating of the fraudulent use of U.K. passport by the killers of a Hamas official in Dubai.
Israel's ambassador to Britain, Ron Prosor, met with Sir Peter Ricketts, head of the British diplomatic service, on Thursday after London asked him to clarify what it called an "identity theft" in which the passports of six British Israelis were used by assassins.
"The permanent secretary (Ricketts) said we wanted to give Israel every opportunity to share with us what it knows about this incident," Miliband told British television.
"We hope and expect they will cooperate fully with the investigation that has been launched by the prime minister [Gordon Brown]," he said.
He said he hoped to discuss the issue further with Israeli Foreign Minister Avigdor Lieberman when both men were in Brussels on Monday.
A hit squad that killed senior Hamas official Mahmoud al-Mabhouh in a Dubai hotel room in January apparently forged travel documents bearing the names of the Britons, who all live in Israel.
"Following an invitation yesterday evening, I met today with Sir Peter Ricketts, Permanent Under Secretary of the Foreign and Commonwealth Office," Prosor said following the lunchtime meeting.
"Whilst of course happy to cooperate with Sir Peter's request, I was unable to shed any further light on the events in question," Prosor continued.
"In keeping with standard diplomatic practice, it would be improper to disclose the content of such bilateral discussions between our countries."
Prosor added: "In accordance with accepted diplomatic protocol, it would be unfitting to reveal the content of the talks conducted between the countries."
Although Jerusalem has not taken responsibility for the January 20 hit on Mabhouh, the incident seems to have spawned a serious diplomatic rift between Israel and the United Kingdom.
Israel's ambassador to the Republic of Ireland, Zion Evroni, said Wednesday that he too had received a summons from the country's Department of Foreign Affairs and would be meet Minister Michael Martin on Thursday.
In Jerusalem, Foreign Ministry officials declined to comment on the matter, but an Israeli diplomat said on condition of anonymity that the government has decided to withhold a public statement until the British message is received, and would then choose how to respond.
Israeli officials expressed concern Wednesday that the affair could seriously harm ties between Jerusalem and London. They said the British and Irish summonses could lead to similar steps on the part of France and Germany, other countries whose passports the assailants carried in Dubai.
One Israeli official said the Irish government had already contacted Britain, Germany and France to recommend they conduct a joint investigation into the incident.
British Prime Minister Gordon Brown promised Wednesday that his government would launch an inquiry into the use of the British passports in the operation, but did not cast blame over the alleged forgeries.
"The defrauding of British passports is a very serious issue," a statement from the Foreign Office released Wednesday read. "The government will continue to take all the action that is necessary to protect British nationals from identity fraud."
"The government is involved in a number of strands of ongoing activity in relation to this specific case," the statement said. It cited three specific areas of activity: offering bureaucratic assistance to the affected British citizens living in Israel, investigating the matter fully and summoning the Israeli ambassador for clarification.
"The Serious Organised Crime Agency will lead this investigation, in close cooperation with the Emirati authorities," the Foreign Office said.
Ireland's Department of Foreign Affairs released a statement indicating, "the identities of the persons recorded on the forged passports do not correspond to those recorded on the valid passports carrying the same numbers."
Emirati police said the team left Dubai several hours after the operation - some individually and others in pairs - for destinations in Europe, Asia and Africa.
At a memorial rally for Mabhouh in Gaza Wednesday, leaders of Hamas' armed wing said the group "will never rest until they reach his killers".
Hamas politburo chief Khaled Meshal addressed the rally of several thousand by video link from Damascus.
"We call on European countries to punish Israel's leaders for violating laws," he said. "Israel deserves to be placed on the terror list."