Foreign killers are invariably hired by those who do not want the gunmen to have any traceable link with their victims, with Lt Col François saying the Chevaline massacre had all the hallmarks of a slaying carried out by the Italian or Russian mafia.

As he went up the forest road before the drama, Philippe said he had “heard nothing and come across not a single person, no car, no bike”. This supports the theory that the gunman, or gunmen, were already in place before the shootings, or else had arrived by an isolated mountain path. Philippe said they would have been “able to escape by a winding track called Le Moulin” (the mill) which leads directly on to the main road.

THE BRITISH father murdered along with his wife, mother-in-law and a passing cyclist near Lake Annecy in southeast France last week had secretly met a number of people during his caravan holiday and suddenly moved campsites just two days before the shooting, it has emerged. The revelations, when considered along with the fact that Saad al-Hilli took his family on holiday just when his two daughters were due to start school, adds to speculation that he was a man under pressure.

The British engineer killed in the French Alps ­secretly held extreme anti-Israeli beliefs which could be the key to the massacre that has baffled police, a close friend claims. To his wealthy neighbours, Saad al-Hilli was a devoted family man. But behind closed doors he is said to have spent hours on his computer bombarding Arabic chatrooms with anti-Israeli posts.

“He would forever be talking about how the Israelis were taking over the world and specifically taking over America. He hated Israeli Jews taking big banks and strongholds in America. “He thought 9/11 was an inside job by the Israelis to create hatred against the Arabic nations. After 9/11 his involvement in chatrooms increased dramatically. He was very passionate about his beliefs. He didn’t believe the Jews should be in Israel. He thought the land should be Palestinian. “When I heard Saad and Ikbal had been murdered my first thought was, “What has he said? What has he done?’ I think it’s possible he has offended someone and Mossad has taken offence and put a hit out on him.”

Gary also had access to the family home where Saad went online to post his anti-Israeli rants. He believes police need to look at his friend’s banks of computers to get to the truth of what happened in France. He used a rear upstairs room to house four computers and a laptop worth up to £20,000 which he used to write his beliefs in Arabic forums. Saad also had a number of other PCs in an outside shed which Gary helped to build. The chatrooms Saad used were not only a magnet for hate-filled Islamic fundamentalists... but also for opposing forces trying to identify enemies. Gary believes Mossad – whose secret agents have been responsible for many assassinations – could have been ­tracking Saad’s outspoken views. British security services are already said to have put him under surveillance in the 1990s. Baghdad-born Saad arrived in the UK in the 1970s when his parents fled Iraq and one of his uncles was killed by Saddam Hussein’s henchmen. But he owned land in the war-torn country and often returned.

Last night a source close to the investigation said: ‘She told us there was only one killer, who she called a bad man.’

The news comes as it was revealed that police are looking for for a black Mitsubishi Pajero with British number plates in relation to shooting.

Meanwhile, it is understood that Mr Al-Hilli worked for a satellite company which is being investigated by MI5 over fears it has been targeted by foreign agencies that want to develop hostile spying operations.

A cousin of Mr Al-Hilli, who was contacted in Baghdad but refused to be identified, said: ‘If you investigate and find out about Saad’s job, you will know who’s behind his killing.’ The cousin, who lives in Istanbul but was on a business trip to Baghdad, added: ‘We have been told by the police not to say anything more.’

It is believed that French police are examining Iraqi-born Mr Al-Hilli’s work with Surrey Satellite Technology Limited (SSTL). Intelligence sources said the company had ‘been of interest’ to MI5 for ten years during which time the security service had conducted surveillance operations on British-based individuals who had made contact with SSTL.

It provides state-of-the-art equipment that, in the wrong hands, could be turned into spy satellites. It also stores huge amounts of data obtained from many different satellite missions that might be of interest to another state or competitor company.

SSTL declined to discuss security surrounding the firm, but confirmed that Mr Al-Hilli had been working with it since November 2010 as part of a small team on an unnamed project.

A Whitehall security source also declined to confirm or deny MI5’s interest in the company, saying only that the security service would always ‘follow the intelligence’.

A friend of Mr Al-Hilli said that the engineer was not allowed to go to Iraq during the last Gulf War, even though he told the authorities he was going to see family members.

Clarence Oddman, 47, said: ‘I don’t know why he was not allowed to go, but I know the British Government refused him permission.

Cezus is owned by the Areva group which in 2007 was forced to deny a report in Der Spiegel that it had flouted UN sanctions by providing Iran with enriched uranium.