• Emirate '99% sure' Israeli spies were behind Mabhouh death • Israeli ambassador told to explain use of fake British passports

Interpol should help arrest the head of Mossad if Israel's spy agency was responsible for the killing of a Hamas commander in Dubai, the emirate's police chief said today.

In comments to be aired on Dubai TV, Lieutenant General Dahi Khalfan Tamim called for Interpol to issue "a red notice against the head of Mossad ... as a killer in case Mossad is proved to be behind the crime, which is likely now".

International pressure intensified against Israel's spy service as official "wanted" notices were released for the suspected team of Israeli secret agents accused of participating in the assassination. The faces of an 11-strong alleged hit squad appeared on the Interpol website this morning, 48 hours after authorities in the United Arab Emirates issued arrest warrants for the killing last month of Mahmoud al-Mabhouh.

Their offences are listed as "crimes against life and health". The group stands accused of entering the emirate state using forged or stolen European identities, murdering the militant in his hotel and then fleeing the country on 19 January. The red wanted notices are not international arrest warrants, but allow details of fugitives to be released worldwide with the request that the wanted person be arrested and extradited.

Tamim said that the Dubai authorities were virtually certain that Mossad was behind the assassination of Mabhouh, as the incident threatened to turn into a diplomatic row between Israel and Britain over the use of false British passports.

"Our investigations reveal that Mossad is involved in the murder of Mahmoud al-Mabhouh. It is 99%, if not 100%, that Mossad is standing behind the murder," Tamim told the National newspaper in the United Arab Emirates.

The Israeli ambassador, Ron Prosor, was at the Foreign Office this morning for a brief meeting to "share information" about the assassins' use of identities stolen from six British citizens living in Israel, as part of the meticulously orchestrated assassination of Mabhouh at a luxury hotel last month.

"After receiving an invitation last night, I met with Sir Peter Ricketts, deputy-general of the British foreign minister," Prosor said after the meeting. "Despite my willingness to co-operate with his request, I could not shed new light on the said matters."

Britain has stopped short of accusing Israel of involvement, but to signal its displeasure the Foreign Office ignored an Israeli plea to keep the summons secret. "Relations were in the freezer before this. They are in the deep freeze now," an official told the Guardian.

David Miliband, the foreign secretary, insisted he was determined to "get to the bottom of" how fake British passports were involved in the killing. He said he "hoped and expected" that Tel Aviv would co-operate fully with the investigation into the "outrage".

Gordon Brown launched an investigation yesterday into the use of the fake passports, which will be led by the Serious Organised Crime Agency. The British embassy in Tel Aviv is also contacting the British nationals affected in the plot "and stands ready to provide them with the support they need", the Foreign Office said last night.

"The British passport is an important part of being British and we have to make sure everything is done to protect it," Brown told LBC Radio yesterday.

A UAE official said the number of suspects in the assassination had widened to at least 18. The official said the list included 11 people identified this week, two Palestinians in custody and five others. Two women were among the suspects.

The Israeli newspaper Haaretz named the two Palestinians as Ahmad Hasnin, a Palestinian intelligence operative, and Anwar Shekhaiber, an employee of the Palestinian Authority in Ramallah. They were arrested in the Jordanian capital, Amman, and extradited to Dubai. Both worked for a property company in Dubai belonging to a senior official of Fatah, the political faction headed by the Palestinian president, Mahmoud Abbas, the paper reported.

Israel's foreign minister, Avigdor Lieberman, said there was no proof that Mossad was involved in Mabhouh's killing in a Dubai hotel last month, but added that Israel had a "policy of ambiguity" on intelligence matters.

There were calls in Israel for an internal government inquiry into whether Mossad was responsible for identity theft from dual nationals, and criticism of its chief, Meir Dagan, for what critics described as a clumsy operation that risked alienating European allies.

"What began as a heart attack turned out to be an assassination, which led to a probe, which turned into the current passport affair," a columnist, Yoav Limor, wrote in Israel Hayom, a pro-government newspaper. "It is doubtful whether this is the end of the affair."

Yesterday more details emerged about the assassination plot:

• The Guardian learned that a key Hamas security official is under arrest in Syria on suspicion of having helped the assassins identify Mabhouh as their target.

• Authorities in Vienna have begun an investigation into whether Austria was used as a logistical hub for the operation. Seven of the mobile phones used by the killers had Austrian sim cards.

• Three of the killers entered Dubai with forged Irish passports that had numbers lifted from legitimate travel documents.

It is not the first British-Israeli row over the misuse of British passports. British officials are particularly angry because the Israeli government pledged that there would be no repeat of an incident in 1987, in which Mossad agents acquired and tampered with British passports.