Dubai, UAE (CNN) -- A shadowy figure murdered in his Dubai hotel room by a hit squad that the police say operated with European passports. It sounds like the plot of a John Le Carré spy novel, but this is reality and the hunt is on for the killers of top Hamas official Mahmoud al-Mabhouh.
Retracing his footsteps, here's the picture that emerges: al-Mabhouh landed at Dubai International airport on the afternoon of January 19. Then, a short drive to his hotel, the al Bustan Rotana, where just hours later he would be killed.
Dubai police say he was not traveling under his real name, so the hotel staff would have been unaware he was one of the founding members of Hamas' military wing and was wanted by Israel for more than 20 years.
According to family members, he booked a room on the first floor, making sure there was no balcony and that the windows were sealed so no one could enter.
His brother in Gaza tells CNN he never ate or drank in a hotel or on a plane as he knew he was a target. Dubai police say he then left the hotel, returning around 9:30 p.m. They want to know where he was during that time and, crucially, who he met.
Dubai police refused to talk to CNN, but they told al-Mabhouh's family there were signs of five or six electric shocks on his legs, behind his ears, on his genitals and heart. Blood on a pillow led police to believe he was suffocated.
Lt. Gen. Dahi Khalfan, Dubai's chief of police, has told local media they are looking for a professional gang, many of whom held European passports.
It's believed they left the country even before al-Mabhouh's body was discovered. Dubai police are working closely with Interpol to track the killers and have publicly voiced surprise that such a figure within Hamas was traveling without his own security.
At al-Mabhouh's funeral in Damascus, Syria, where he spent the last years of his life, few doubted Israel was behind the assassination.
At his family home in Gaza there is the same conviction that Israel's intelligence unit, Mossad, was responsible.
His brother Farq al-Mabhouh said: "If you know the purpose of his visit to Dubai then you know the result of 90 percent of the investigation. Some in Hamas say Dubai was a stop off for a third country he was traveling to."
The brother also claims al-Mabhouh ran a textile company, in addition to his Hamas duties, and that he may have been in Dubai for that reason.
Al-Mabhouh's father, Abed al-Rauf, told CNN: "There was an attempt to kill him in Lebanon and he survived, two other attempts in Syria and he survived. Israel has been after him for the past 22 years."
His mother, Fatima agreed, saying she has been expecting him to be assassinated for years.
Israel certainly has good reason to put him on its most wanted list. Al-Mabhouh was behind the kidnapping and killing of two Israeli soldiers in 1989.
Israeli security sources tell CNN al-Mabhouh was a key link between Iran, Hezbollah and Hamas and he was involved in smuggling arms to Gaza. The same sources also point out an arms dealer could have many enemies, not just Israel.
As is its policy on security matters like these, Israel will neither confirm nor deny any involvement in al-Mabhouh's death.
Analysts point to two benefits from this policy: there can be no international repercussions if there is no admission and even if Israel is falsely accused of an assassination, it can only help Mossad's reputation of being able to hit a target wherever and whenever it chooses.
But Mossad has had its public failures. An attempt to poison Hamas leader Khaled Mashal in Jordan in 1997 led to the capture of two Mossad agents. The late King Hussein then forced Prime Minister Benjamin Netanyahu to send the antidote to save Mashal's life and to release Hamas' spiritual leader, Sheik Yassin. A few years later, Yassin was assassinated by Israel in Gaza.
Dubai police have said Mossad could be behind this killing on their territory and has warned Hamas and Mossad to stay away. But the evidence is not compelling yet to lay official blame.