Dubai has identified 15 new suspects in the assassination last month of a Hamas official, and 10 of those suspects share the names of Israelis who hold dual citizenship, Haaretz has learned.

Dubai police said the total number of people believed involved in the death stands at 26. Hamas military commander Mahmoud al-Mabhouh was killed last month in his hotel room in what Dubai police have said they are near certain was a hit by Israel's Mossad spy agency. Police said the killers travelled to the Gulf Arab emirate using European passports.

Dubai authorities had earlier named 11 suspects, who they said travelled on fraudulent British, Irish, French and German passports to kill Mabhouh. Six were Britons living in Israel who deny involvement and say their identities were stolen.

"Dubai investigators are not ruling out the possibility of involvement of other people in the murder," the statement said.

The suspected killers' use of passports from countries including Britain and France has drawn criticism from the European Union that diplomats said was aimed at Israel. Some of governments involved have summoned their Israeli ambassadors.

"Friendly nations who have been assisting in this investigation have indicated to the police in Dubai that the passports were issued in an illegal and fraudulent manner," the Dubai government statement said.

It said that pictures on the passports did not correspond to their original owners.

In a statement on Monday that European diplomats said was intended as a rebuke to Israel, EU foreign ministers said that the assassination was "profoundly disturbing."

Israel has not denied or confirmed it played any role but Foreign Minister Avigdor Lieberman said there was nothing to link it to the killing. The United States, Israel's main ally, has kept silent about the affair.

The new suspects were identified as: Daniel Marc Schnur, Gabriella Barney, Roy Allan Cannon, Stephen Keith Drake, Mark Sklur and Philip Carr, traveling on British passports; Ivy Brinton, Anna Shauna Clasby and Chester Halvey, on Irish passports; David Bernard LaPierre, Melenie Heard and Eric Rassineux, on French passports, and Bruce Joshua Daniel, Nicole Sandra McCabe and Adam Korman on Australian passports.

An Israeli Foreign Ministry spokeswoman in London on Wednesday said, "We will seek to make contact with these individuals and offer consular assistance as we have the previous individuals."

Dubai police said the suspects arrived from cities including Zurich, Paris, Rome, Milan and Hong Kong.

"This was to take the camouflage and deception to its utmost level and to guarantee the avoidance of any security supervision or observation of their movements," the statement said.

Once their part in the operation was completed, the suspects again dispersed to different parts of the world, with two suspects leaving Dubai by boat for Iran, it said.

Dubai police also released credit card details of some of the suspects. At least 13 credit cards used to book hotel rooms and pay for air travel were issued by the same small U.S. bank.

Two Palestinians suspected of providing logistical support were in detention and Dubai's police chief has said he believes the operation could not have been carried out without information from inside Hamas on Mabhouh's travel details.

An official from the movement was quoted as saying last week that Hamas had launched an investigation to try to discover "how the Mossad was able to carry out the operation.

Mabhouh's killing was the third high profile murder in less than two years in trade and tourism hub Dubai, one of seven emirates in the UAE federation, where violent crime is rare.  He said forensic tests indicated al-Mabhouh died of suffocation, but lab analyses were still under way to pinpoint other possible factors. Hamas initially claimed al-Mabhouh was poisoned and electrocuted, but later a Hamas leader, Mohammed Nazzal, denied that poison was used. The killing itself took just 10 minutes.