LONDON/TEL AVIV/VIENNA/BERLIN – Britain and Ireland called in Israel's envoys on Thursday over the use of fake passports by the killers of a Hamas chief last month, as Dubai's police chief said he was sure Mossad was behind the murder. Israel's Ambassador to London, Ron Prosor, was called in for talks with a senior official at the Foreign Office, the day after Prime Minister Gordon Brown demanded an "full investigation" into the passports row. Irish Foreign Minister Micheal Martin also held "frank" talks with Israel's envoy – diplomatic code for potentially angry exchanges – saying he regarded the use of false Irish passports as "an extremely serious incident". "We will have a frank discussion with the ambassador," said Martin ahead of the meeting. "We are putting pretty direct questions and seeking assistance and clarification. We want to get answers as quickly as we possibly can.” "You can decode what I am saying. It is a very serious situation," he added, shortly before the talks between Israeli Ambassador Zion Evrony and the head of Ireland's Civil Service. Diplomatic tensions have mounted over the killing of Mahmoud al-Mabhouh last month in a luxury Dubai hotel, ever since the emirate's police chief revealed that 11 European passport holders were allegedly involved. Austria is now investigating whether Austrian telephones were used to plan the killing. No government has directly accused Israel but speculation about the killers has centred on Israel's Mossad intelligence services, which have used agents with fake passports for such operations in the past. Dubai police chief Dahi Khalfan Tamim said yesterday he was 99 per cent sure Israel was involved in the killing of a Hamas commander al-Mabhouh at a Dubai luxury hotel, according to a report published yesterday in an Emirati newspaper. "Our investigations reveal that Mossad is involved in the murder of al-Mabhouh. It is 99 per cent, if not 100 per cent, that Mossad is standing behind the murder," Tamim told The National newspaper. Meanwhile, Mossad chief Meir Dagan sees no reason to resign over a scandal-fraught assassination in Dubai, and Prime Minister Benjamin Netanyahu is unlikely to ask him to, a confidant of the Israeli spymaster said yesterday. Discerning a Mossad modus operandi and predicting a stink over the trans-national identity thefts, some Israeli pundits suggested Dagan would be forced to step down – like predecessor Danny Yatom in 1997 after a botched assassination in Jordan. But the confidant, who asked not to be identified, told reporters: "Dagan has no intention of quitting before his tenure is completed". Resignation would be tantamount to taking responsibility, the confidant said. The hotel-room hit on Mabhouh was dressed up as death by natural causes but was uncovered more than a week later when UAE police launched a murder probe at Hamas urging. In Vienna, Austrian authorities are investigating a possible link in the assassination of the Hamas leader in Dubai, following indications that the killers used Austrian mobile phones, the Interior Ministry's spokesman confirmed yesterday. 'Austrian mobile phones were allegedly used in the preparation of the crime,' said spokesman Rudolf Gollia. There had been contact with Dubai authorities; and Austrian authorities started investigating on Monday. However, police have not yet come up with any findings, Gollia added. In Berlin, Germany's foreign intelligence service BND refused to comment on an Arab newspaper report, which alleged that a German national was implicated in the killing of al-Mabhouh in the United Arab Emirates, German press said yesterday. Meanwhile, a spokeswoman for the German Federal Crime Office confirmed that her agency was dealing with the case. "We are exchanging information with the police in Dubai," she said. She added the German Embassy in the UAE had yet to get involved in the murder file of al-Mabhouh. Germany and Israel have a very deep military and intelligence co-operation whose details remain highly secretive to the German public.