Dubai, United Arab Emirates (CNN) -- It was something straight out of a James Bond film: A team of alleged killers in a swank Dubai hotel, some of them scoping out their target in an elevator while dressed in tennis clothes and carrying rackets and backpacks.

The suspects, seen on security videotapes, fall short of the dashing and debonair assassins seen on film. They are ordinary, unremarkable. They do not stand out or draw attention to themselves. But their mission, according to Dubai police, was a chilling one: the cold-blooded murder of a top Hamas official.

And that alleged mission was a success -- the body of Mahmoud al-Mabhouh, a founding member of Hamas' military wing, was found in his hotel room the following day, January 20.

Authorities have not said how al-Mabhouh died, but told his family there were signs of electric shocks on his legs, behind his ears, on his genitals and over his heart. Blood on a pillow led police to believe he was suffocated. The killers left some of al-Mabhouh's medicine next to his bed in an apparent effort to suggest his death was not suspicious, police said.

Dubai police on Monday named 11 suspects in the case -- 10 men and a woman -- and released their pictures. An international arrest warrant was issued Tuesday.

Officials involved in the investigation, however, have told CNN there are 17 suspects involved -- one Palestinian and 16 Europeans -- although only 11 names have been released. Some suspects were in touch with others outside the country, the officials said.

One of the Palestinians -- a man believed to have met, at the airport, the alleged mastermind, a man from France who is seen on closed-circuit television handing him an envelope -- was arrested in Jordan, and led authorities to a second Palestinian. Both of the Palestinians were living in the United Arab Emirates and had residential visas, authorities said. They have been returned to Dubai, where they remain in custody.

But questions remain about who the suspects are -- and who they were working for. Police have said the 11 were holding European passports -- one from France, three from Ireland, six from Britain and one from Germany.

The British government, however, has said it believes the passports used were fraudulent. On Wednesday, the French government said the passport from that country also was fraudulent. Ireland said it was unable to find any record of passports being issued with details that have been reported in the UAE.

British Prime Minister Gordon Brown has called for a full investigation into the alleged fraudulent passports.

Meanwhile, the passports have caused consternation in Israel, where up to seven people are wondering how their names got on the travel documents. They deny any knowledge of al-Mabhouh's death.

Hamas has called al-Mabhouh's death an "assassination," and mourners at his funeral in Damascus, Syria, speculated that the Israeli intelligence unit, Mossad, was behind it. Al-Mabhouh, according to Hamas, was behind the kidnapping and killing of two Israeli soldiers in 1989.

"The decision for revenge has been made and the Zionists must wait for that moment and see," said Abu Ubaida, a spokesman for Al-Qassam Brigades, the armed wing of Hamas.

Israeli security sources have told CNN that al-Mabhouh was a key link between Iran, Hezbollah and Hamas and he was involved in smuggling arms to Gaza. The same sources also pointed out an arms dealer could have many enemies, not just Israel.

Israel has a stated policy on security matters of neither confirming or denying involvement, and government officials in Israel denied comment on the "assassination" statement.

"The Israeli policy has always been to be vague regarding security activities, and that is the right policy," Foreign Minister Avigdor Lieberman told Israel Army Radio on Wednesday.

But, he said, "There is certainly no reason to think that the Mossad and not some other intelligence agency of another country operated there."

According to police, the suspects arrived in Dubai the day before the killing. Five of them carried out the crime while the remaining six served as lookouts, police said. The suspects stayed in different hotels, used only cash and did not talk to each other on the phone.

Dubai police have said the alleged mastermind stayed at a luxury hotel in Dubai, but also booked a room at the al Bustan Rotana hotel, where al-Mabhouh was killed.

The French suspect requested Room 237 -- directly across from where al-Mabhouh was staying in Room 230, police say -- but the suspect apparently never stayed there. Instead, police say the rest of the group used the room to plot the killing and the alleged mastermind left the country before it was carried out.

Footage on security cameras at Dubai International Airport show one of the suspects following al-Mabhouh after he landed, police said. Two others followed him once he arrived at the hotel, police said, taking the same elevator dressed as tennis players and ensuring al-Mabhouh was staying in Room 230.

Police said they believe the suspects entered al-Mabhouh's room about 8 p.m. after the hotel cleaning crew finished their rotation on the floor, using an electronic device to gain entry.

Al-Mabhouh entered his room at 8:25 p.m., hotel security cameras and an electronic read-out of his room key show. Police say it was no more than 10 minutes before the suspects left the room and headed immediately to the airport, where they boarded flights to various cities in Europe and Asia, police said.

Before leaving, police said, the group took great care to make sure the room looked orderly, removing anything that might indicate a struggle. The suspects also deliberately turned the safety lock on the room door from the inside in order to suggest the death was normal, police said.

The alleged assassination plot is "not that surprising," Gary Berntsen, a former officer and longtime CIA operative, told CNN's Anderson Cooper on Tuesday.

"The question is whether the government or the organization that wanted to do it had the will to do it," he said. "Assassinating somebody like that is not that difficult. It's a matter of will."

The case has caused a furor in Israel, however, as up to seven people have the same names as suspects in the case. None resembled the photos released by police, however, and several have denied involvement to the media.

"I am simply in complete shock," one of them, Stephen Daniel Hodes, told CNN. "I don't know what is happening. ... I don't know how they reached me. This isn't a picture of me, of course. I don't know who took my details or how they got them. I haven't left the country in, I think, two years, and I've never been to Dubai. I don't know what is happening and I'm simply afraid."

Another man, British-board repairman Paul John Keeley, told the Israeli daily newspaper Haaretz, "I'm in shock -- I just don't understand how something like this could happen."

"From the moment I heard about it I was very worried. I'm worried for my family," said Keeley, 43 and the father of three. "I don't know who a person calls when their identity is stolen. I'm waiting for someone from the British or Israeli government to contact me and give me answers."

Government officials working as part of the investigation team told CNN that the passports were used in trips to Europe and Asia during the last six months, and some were used to obtain credit cards and rental cars.

Haaretz's education correspondent, Or Kashti, bears a striking resemblance to one of the suspects' photos. In a column Tuesday, he wrote that even his mother asked him if he'd been abroad recently.

Asked about the allegedly fraudulent passports and the expertise required to do it, Berntsen, the former CIA operative, told CNN, "There are a lot of countries that can do this. ... When we entered Kabul (Afghanistan) in 2001, we found that the Taliban themselves had been doing, you know, photo substitution on passports. ... It's not that complicated."

The Israeli government or Israeli security services isn't necessarily responsible, he said. "We have had cases where Americans decided to go off and participate in operations as mercenaries. I don't see why, you know, you wouldn't see individual businessmen doing the same thing."

CNN's Caroline Faraj, Kevin Flower, Alanne Orjoux, Ashley Hayes and Paula Hancocks contributed to this report.