By Jonathan Marcus
BBC News Diplomatic Correspondent
Alleged suspects dressed in tennis gear before Mr Mabhouh was killed
"A tactical success but a strategic failure" - that is how one Israeli newspaper described the operation to kill Hamas figure Mahmoud al-Mabhouh.
The operation was clinical. The hit-team successfully escaped Dubai. But they left telltale traces.
The false foreign passports used by the alleged team of secret agents have been identified and six of them are British.
That is diplomatic problem number one.
Israel has used fake British passports in its operations before; Israel was cautioned about this by the British authorities in 1987.
Problem number two is identity theft.
The passports used the names of real people, British citizens, with dual nationality, who happen to live in Israel, who had absolutely no knowledge of what was going on.
The British government has a responsibility to its passport holders wherever they live.
We've got to carry out a full investigation into this
Gordon Brown British Prime Minister
These people have been put in an invidious position by somebody.
The British Prime Minister Gordon Brown is not pointing the finger at anyone yet.
But speaking to a local radio station in London - LBC 97.3 FM - he made it clear that his government wants answers.
"We've got to carry out a full investigation into this," he said.
"The British passport is an important document that has got to be held with care.
"The evidence has got to be assembled about how it actually happened and why it happened and it's necessary for us to accumulate that evidence before we can make statements."
That may suffice for now, but it is clear that the political pressure on him is growing.
The shadow foreign secretary, William Hague, has also called for answers.
Avigdor Lieberman has not denied Israeli involvement outright
"The reports that the identities of real British citizens have been cloned to produce forged passports is a matter of great concern," he said.
He has set out a number of questions about the affair which he wants Gordon Brown to answer.
Other British parliamentarians have weighed in too, one calling for Israel's Ambassador to be summoned to the Foreign Office.
For now Britain is looking to establish the facts of the case.
French, German and Irish passports were also apparently used in the operation and those governments will also be wanting some answers.
Nobody yet of course has any proof-positive as to who carried out the operation.
Israel's Foreign Minister Avigdor Lieberman has not denied Israeli involvement outright, saying merely that Israel has a "policy of ambiguity" on intelligence matters and that there was no proof that it was behind the assassination.
There may be no "smoking gun".
Nonetheless what you might call the "smouldering passports" - or at least their electronic scans - suggest that Israel has some questions to answer.
Police say Mr Mabhouh was murdered in a Dubai hotel room
Over recent years there has been growing external criticism of Israel which has hardened in the wake of the Gaza War.
Many in Israel see this as an explicit campaign to de-legitimise their country and even friendly foreign governments have engaged with Israel to explore how its deteriorating image can be improved.
If Israel was indeed behind this assassination then some, even in Israel, may well suggest that they have scored a costly own goal.
Police in Dubai have released images of 27 people they believe are behind the killing of a senior Hamas commander. The suspects are accused of using fake passports bearing their own pictures, but the names of innocent citizens.
Twelve of the passports used were British (shown on previous slide). The other 15 on the list are reported to have used stolen identities from Australian, French, Irish and German citizens.
The 27th suspect used the alias Joshua Aaron Krycer - a stolen Australian identity (pictured left). Police say the suspects used their fake documents to travel to Dubai in groups, flying from Zurich, Rome, Paris and Frankfurt.
One of the victims of the identity theft was British-Israeli Paul John Keeley (pictured right). The passport used by one of the suspected assassins bore his name, but featured a photograph of another man (pictured left).
Palestinian militant Mahmoud al-Mabhouh was killed in his hotel room in Dubai on 20 January. Police claim one of the suspects, pictured on the left, went to a hotel to put on a disguise. He is seen leaving a toilet wearing a wig.
Surveillance cameras also recorded Mr Mabhouh, circled in red above, at the hotel's reception before his death. At the bottom of the image the head of one of the suspects can be seen. As Mr Mabhouh leaves, the suspect follows.
Mr Mabhouh is trailed into the lift by a number of the suspects, including two pictured here in tennis gear. Investigators believe he had been followed from Syria to Dubai where it is thought he wanted to buy weapons for Hamas.
When Mr Mabhouh leaves the lift, police say two of the suspects can be seen following him down the corridor. He was later found dead in his room. A post-mortem report said he had been electrocuted and suffocated.
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