Alps murders: Was Eastern European assassin paid just £1,680 to kill the Al-Hilli family? Iraqi-British engineer Saad Al-Hilli, his wife and her mother all shot dead The Al-Hilli's daughters, Zainab, eight, and Zeena, five, both traumatised Claims that a contract for an assassin could be linked to inheritance dispute Suggestions the family was targeted by a 'mercenary' from the Balkans Theory: A hired assassin with military experience may have murdered a British family and a French cyclist in the Alps for just £420 each, a witness has claimed. Engineer Saad al-Hilli, pictured, was killed alongside his wife and her mother A hired assassin with military experience may have murdered a British family and a French cyclist in the Alps for just £420 each, a witness has claimed. The chilling claim was released today on the first anniversary of the massacre which left Iraqi-British engineer Saad Al-Hilli, 50, his wife Ikbal, 47, and her mother Suhaila al-Allaf, 74 all dead. One French investigating source said: 'The contract could be linked to an inheritance dispute within the Al-Hilli family.' The source confirmed that an 'English witness' had suggested the entire Al-Hilli family was targeted by a 'mercenary' from the Balkans who was paid the equivalent of just £1680. British police officers involved in the Anglo-French investigation have so far refused to comment on the enquiry, but their counterparts in Annecy confirmed that suspicions about a contract killing are 'high on the agenda'. French cyclist Sylvain Mollier, 45, was also killed in the shootings, close to Lake Annecy in France. The Al-Hilli's daughters, Zainab, eight, and Zeena, five, who were both in the car, were left orphaned and traumatised following the shooting on September 5 last year. A total of 21 bullets were used, with none damaging the bodywork of the family BMW in which the Al-Hillis were sitting. Instead, bullets passed straight through a car window before finding their human targets. At least five others ended up in the body of the cyclist, Mr Mollier, with the gunman reloading at least twice, ballistics reports suggest. French detectives are also following up claims that a French convict was offered '100,000 euros (£84,000) 'to eliminate an Iraqi settled in England', according to today's Le Figaro newspaper. Grim: A source says an 'English witness' suggested the entire Al-Hilli family was targeted by a 'mercenary' from the Balkans. This shows the family car at the murder scene The horrific killings of the Al-Hilli family in one of the most scenic areas in the French Alps has baffled detectives. Since the murders a year ago, a number of theories have emerged as to why the family were slaughtered. French investigating sources believe an inheritance dispute within the Al-Hilli family could be a motive. Speculation: The killings in the French Alps have left a trail of suspected theories. This shows French Gendarmes close to the murder scene last year There have also been revelations of a possible connection to the former regime of Saddam Hussein. It followed claims that the deposed tyrant may have deposited £840,000 into a Swiss bank account in the name of victim Said al-Hilli's father. At one stage, detectives believed they had been shot by a serial killer with a hatred of tourists. Police said they had linked the murders of the British family with the mysterious death of another tourist last July. Other theories have speculated that the French cyclist Sylvain Mollier, a 45-year-old nuclear industry worker, was the primary target. There have also been claims that a mystery motorcyclist seen around the Alpine beauty spot could have carried out the killings. This suggests that someone may have explored a number of options before finally ordering a hit. Saad's brother Zaid Al-Hilli, 54, was arrested at his home in Surrey in June on suspicion of conspiracy to murder, but has since been bailed. Zaid, who has proved he was in the UK this time last year, denies any wrongdoing and there is no concrete proof for any of the claims about the killings being commissioned. Suspect: Saad's brother Zaad Al-Hilli, 54, pictured, was arrested at his home in Surrey in June on suspicion of conspiracy to murder but has since been bailed But the French now routinely leak information allegedly linking Zaid to the murders, while attempting to close down other lines of enquiry. Annecy prosecutor Eric Maillaud said the brothers were in dispute over their father's inheritance, which included the £1 million family home in Claygate, Surrey. 'Saad was scared of his brother,' said Mr Maillaud. 'It's for this reason that he changed the locks of the house.' Today there were also claims from the French sources that the brothers had a 'visceral hatred' for one another and that Saad's 'paranoid fear' was so great that he kept an illegal Taser stun gun for personal protection. Saad had also started using satellite technology through his smart phone which enabled friends to track his every move. The brothers' father, Kadhim, died in Spain two years ago aged 85, leaving several properties and the equivalent of more than £600,000 in a Geneva account. The French now claim Zaid had attempted to 'siphon' money from the account, and to fabricate his father's will in his favour. However, Mr Maillaud admitted that there was currently not enough evidence to charge Zaid, and that other theories could not be discounted. The murder scene - an isolated mountain layby - reopened a few days after the killings, and today floral tributes were already beginning to appear where the family BMW had been parked. Probe: Sources close to the investigation have suggested that the killings could be linked to an inheritance dispute within the Al-Hilli family. But no evidence has been produced to support the suspicions. This is Saad Al Hilli's home Saad's seven-year-old daughter, Zainab, was beaten over the head with the butt of the suspected murder weapon - a Luger P06 in 7.65mm Parabellum. Her four-year old sister, Zeena was left deeply traumatised after hiding beneath the skirts of her dead mother in the back of the BMW for eight hours before being discovered by gendarmes. Both girls are now in the care of extended family, following a court battle with surrey social services who wanted to keep them with foster parents. French police still believe they may still unlock the secrets of what happened through finally remembering what they saw.