French authorities were investigating whether the massacre of three members of a British family was related to a feud between brothers about money.
Prosecutor Eric Maillaud said a "family drama" between two brothers could be behind the mass killing in which Saad al-Hilli, 50, was gunned down alongside his dentist wife, named by neighbours as Iqbal, and a woman believed to be her mother.
"It seems that there was a dispute between the two brothers about money. This seems to be credible information coming from the British police," Maillaud said, according to AFP.
Police near the scene of the murders in the French Alps
The couple's four-year-old daughter, named locally as Zeena, was found alive in the BMW estate underneath the bodies of her relatives around eight hours after the massacre, which also saw a passing French cyclist, Sylvain Mollier, 45, shot dead.
The al-Hillis' seven-year-old daughter, believed to be called Zainab, was in a medically induced coma in Grenoble University Hospital after being repeatedly beaten around the head and shot in the shoulder in the attack, which took place on Wednesday.
Three of the four who were killed were shot in the middle of the head, French police said.
On Friday authorities prepared to carry on post-mortem examinations on the bodies of four people. Police are hoping to question the al-Hillis' four-year-old daughter on Friday to gain insight into the incident.
On Thursday a neighbour of the couple gave a clue to the family's killing on live radio. Jack Saltman told the Richard Bacon show on Radio 5 Live yesterday: "I know one little thing which I am not prepared to speak (about) at the moment. I will tell the police about it.
"It was something Saad said to me before he went, but at this stage I do not feel I can disclose that, but I will tell the police exactly what he told me before he left."
Another of the family's neighbours in the upmarket village of Claygate in Surrey said he was going to alert police to something Mr al-Hilli said to him before travelling to the Le Solitaire du Lac campsite in Saint-Jorioz, close to the Swiss border.
According to a family friend, known as James, Mr al-Hilli said his family moved to the UK in the 1970s after Saddam Hussein’s Ba’ath party looked “unfavourably” on their mechanical engineering business.
It was reported in the Daily Mail that Mr al-Hilli was known to the security services and was put under Metropolitan Police Special Branch surveillance during the second Gulf war.
French police continued to try and establish what happened today and the man heading up the investigation into the killing spree played down suggestions of "professionalism" in the attack.
Public prosecutor Eric Maillaud told a press conference yesterday: "I won't say it was professional, what I will say is it was tremendous savagery. And what is certain is that somebody wanted to kill."
Police stand in the garden of a house in Claygate believed to be owned by murdered family
The powerful BMW, which has now been moved by police, was discovered surrounded by spent bullet cartridges in a car park near footpaths on the outskirts of a forest near Lake Annecy, a picturesque region popular with tourists.
The firearm used is believed to have been an automatic pistol.
A British cyclist, a former RAF serviceman who had been overtaken by the French rider, discovered the grisly scene in a quiet car park, Mr Maillaud said.
He is believed to have put the injured seven-year-old in the recovery position and immediately called the emergency services.
The prosecutor defended the delay in finding Zeena as he revealed she was receiving psychiatric treatment
Reports have suggested that police only realised there were two young girls in the family when they interviewed fellow holidaymakers at the campsite where they were staying.
Both sisters are reportedly under police protection while detectives are set to question the traumatised four-year-old as soon as possible to see if she holds vital evidence about the killings.
French president Francois Hollande yesterday offered his sympathy to those affected by the massacre and vowed that authorities would do their utmost to find the perpetrators.
"Our police are co-operating and everything that is found will be shared," he said.