The French authorities have been accused of a cover up by the brother of a British tourist who was brutally shot dead in the Alps alongside his wife and mother-in-law in 2012, in a mystery that remains unsolved to this day.

Saad al-Hilli was gunned down alongside his wife, Iqbal Al-Hilli, 47, and her mother, Suhaila al-Allaf, 74 in September 2012.

The al-Hilli’s two daughters - seven and four - miraculously survived.

A cyclist, Sylvain Mollier, 45, was also killed in the massacre in the isolated layby close to Lake Annecy, in eastern France.

Now, Mr al-Hilli’s brother Zaid al-Hilli has slammed the French investigation and claimed they went ‘the wrong way’ in their search for the killer, pointing fingers at him instead of local suspects.

He called the original investigation a ‘deception - an attempt to deceive us’.

The three fatal casualties were brutally shot three times each with at least one shot to the head and the case has remained a mystery for 12 years.

During the bloodbath, the al-Hilli’s seven-year-old daughter, Zainab Al-Hilli, was left for dead after being shot in the shoulder and beaten around the head.

Her sister, Zeena Al-Halli, four, escaped by hiding underneath her mother’s legs and remaining motionless for eight hours in the back of the family’s BMW.

Police found her alive.

Now Mr al-Hilli has called for investigators to search for more local suspects after he was wrongly arrested in 2013 in a bid to finally close the case which has puzzled police for more than a decade - while accusing French officials of a cover up.

‘The original investigation was a deception, to attempt to deceive us,’ he said, according to The Times. 'It was a local crime and has been covered up.

‘They made allegations against me without any evidence. There was no attempt to look at a local motive right from the start.’

And progress could now be made after French police revealed earlier this week that DNA testing might be able to solve the baffling cold case.

Investigators from France’s elite cold case unit in the Paris suburb of Nanterre have ordered the ‘unsealing of the fragments’.

The clothes Sylvian Mollier and Zainab Al-Hilli were wearing on the fateful day are also going to be reexamined, along with some 10 cigarette butts found around the area.

More than two dozen spent bullet casings were found near their British-registered BMW estate car.

‘It is hoped that new examinations will uncover DNA traces,’ said an investigating source. ‘If yes, then they will be sent for comparison with a national genetic fingerprint file which lists more than four million fingerprints, to see if there is a match.’