Journalists wait in front of Gendarmes, who block access to a site where people were shot to death near Chevaline, French Alps, Thursday Sept. 6, 2012. A 4-year-old British girl hid for eight hours beneath the bodies of slain family members in the back of their car before she was discovered by French investigators who had been guarding the vehicle, a prosecutor said Thursday. Three people  a man and two women  had been shot to death, as was a French cyclist whose body was found nearby. (AP Photo/Laurent Cipriani)

Grenoble, France - French police will Saturday launch a fresh appeal for information they hope will lead to a breakthrough in the probe into the slaying of four people in an Alpine beauty spot.

A month after three members of a British-Iraqi family and a local man were shot dead, investigators remain completely baffled about the identity of the killer and the motive for an extraordinarily brutal attack.

“Everyone is working hard, but there has not been any miraculous discovery that could change the course of the investigation,” admitted Eric Maillaud, the prosecutor in the holiday town of Annecy.

Maillaud is in charge of an investigation aimed at finding the killer or killers of 50-year-old Saad al-Hilli, his wife Iqbal, 47, her mother Suhaila al-Allaf, 74, and Frenchman Sylvain Mollier, 45.

Maillaud revealed that he has been studying pictures taken by the Hillis on September 5 in the hours before the attack, which their two young daughters survived.

“We will be issuing a fresh appeal for witnesses on Saturday. There could be someone who saw something important that could progress the inquiry, whether it was just seeing the family car drive past or other vehicles.

“Even if it is just a matter of allowing us to establish the exact movements of the family, it could help.”

The fact that all four victims had been shot at least twice in the head was initially interpreted as a sign that the killings had been the work of a professional killer.

Maillaud now thinks that theory “less likely.”

“It is hard to imagine a hardened, highly-paid killer firing more than 20 bullets,” he told AFP.

Police found at least 25 cartridges at the scene and sources have told AFP that forensic examination of them indicated they were all fired from one gun Ä a detail Maillaud has refused to confirm or deny.

Although an exhaustive search of the Hilli house in the London suburbs apparently did not produce anything that could have shed light on a possible motive for the shooting, the French team continue to belileve that something in the family's background is the most likely explanation.

“No one theory is being given priority, which is not to say the investigation has reached a dead end, quite the contrary,” said Benoit Vinnemann, the senior gendarme on the inquiry team. “There have been new avenues of inquiry that have opened up.”

The investigators have been building up a detailed profile of the assets of the late father of Saad al-Hilli, following suggestions early in the inquiry that a disputed inheritance could be linked to the murder.

That theory has been dismissed by Saad's brother Zaid, who has been interviewed several times on a voluntary basis by police in England.

Newspaper La Tribune de Geneve reported in its online edition Friday that Swiss authorities had seized money in a Geneva account linked to the killings.

The newspaper said Saad al-Hilli had been to Geneva shortly before the killings and that it had information thst the trip and the seized funds “are linked to the murders”.

The only known witness to the killing was seven-year-old Zainab al-Hilli, who nearly died after being shot in the shoulder and hit repeatedly around the head by the attacker, but she has been unable to help the enquiry in any meaningful way.

Her four-year-old sister survived the attack by sheltering under her mother's skirt in the back of the family's BMW estate car.

“There are no plans to interview Zainab again,” Maillaud said. “I think the only way we will be able to get anything from her would be from what she says to social workers or members of her family.”

The investigators contacted satellite operators who may have registered images of the scene, without success, and are still examining the Hillis' car in a bid to ensure they have extracted every last fragment of bullet and estabished as much information as possible about its movement in the lead-up to the killings. - Sapa-AFP