The media reports of Mr Mahbhouh's killing have formed two scenarios surrounding his trip to Dubai.
Amid all the speculation about who killed Mahmoud al-Mabhouh, a question remains: What was he doing in Dubai?
Hamas have refused to comment on the reasons for Mr Mabhouh's trip and they have limited their public pronouncements to promises of revenge against Israel.
But why would a known militant leader - reportedly "at the top" of an Israeli hit list - leave the protection of Syria and his bodyguards to go to Dubai in the "Westernised" United Arab Emirates?
The media reports have concentrated on two different scenarios, the first involving a planned arms deal, the second an altogether more shady conspiracy.
THE ARMS DEAL
According to the first scenario, a Mossad hit team found out about a planned arms deal set to go ahead in Dubai, and quickly arranged to take their chance and kill the top Hamas militant before he could buy more weapons to target Israel.
Mr Mabhouh was, by Hamas's own account, responsible for supplying militants in the Gaza Strip with arms they used to fight the Israelis, most notably during the Israeli Cast Lead offensive in December 2008 and January 2009.
Hamas said Mr Mabhouh was "on a mission" when he was killed, Israel's Ynet News reported.
According to the Dubai police he was travelling under an alias - Mahmoud Abdul Raouf Mohammed.
Media reports have said that mission was to buy more rockets for Hamas from Iran.
Dubai has been described as "anyone's bank"
Dubai would be a good place to pick up the money for this deal, the Israeli media have suggested.
The left-leaning newspaper Haaretz said Dubai was known to be a place where "anyone can bank".
"Half the money al-Qaeda spent on 9/11 attacks was sent to the perpetrators in the United States through Dubai banks," the newspaper reported, along with other examples of how "terrorists" had routed finance through Dubai.
Dubai is also the nexus of Iranian sanction-busting, according to Haaretz, with thousands of Iranian companies registered there.
According to Iranian figures quoted by Haaretz, there was a projected $15bn of trade between Iran and Dubai.
"Were the arms deals that Mr Mabhouh reportedly did with Iran part of this vast trade? There is no reason to think differently," Haaretz commentator Zvi Barel wrote.
But other media accounts say he travelled to Dubai under his real identity.
Quoting a Hamas spokesman, Talal Nasser in Damascus, Ynet News reported Mr Mabhouh had travelled to Dubai many times without using an alias and had not encountered any problems.
The report also said he had five identities which he could have used, but did not.
It has been established that Mr Mabhouh went to Dubai without his usual security team.
He was relaxed enough about the trip to continue with his plans when his bodyguards couldn't get tickets on the same plane.
"He would take his bodyguards with him wherever he went, but there was no room for them on the flight," Mr Nasser was reported as saying.
The bodyguards had to buy tickets to join him the next day, Ynet News reported.
Hamas is mourning Mr Mabhouh, but did someone double cross him?
The plane and hotel booking were made only a day before he travelled, according to Dubai police.
Two unnamed Palestinians who tried to flee the United Arab Emirates to Jordan last week were arrested and are being interrogated by the Dubai police.
They believe at least one of these Palestinians had contact with the hit team before Mr Mabhouh was murdered.
The Jerusalem Post reported suspicions voiced across the region that the Palestinian Authority, run by Hamas's rival organisation Fatah, might have had a hand in the attack.
But on Wednesday night the Guardian reported that a third Palestinian, this time a Hamas official, was being interrogated by Syria in connection with the operation.
Dubai police have suggested the hit team was based in Austria, a fact they arrived at from telephone records.
But they were waiting in Dubai for Mr Mabhouh, even at such short notice.
They apparently had enough time to plan and execute a complex operation involving as many as 17 operatives, disguises and radio communications, as reported in the media.
All this leads to another question: Does the hit team's detailed knowledge of his itinerary, the lack of bodyguards and the possibility he was comfortable travelling on his own identity, paint a scenario where Mr Mabhouh was served up to his assassins in Dubai by people he trusted?