The four-year-old girl who survived the execution-style killing of her family in the French Alps was due to return to Britain on Sunday as police again quizzed relatives and scoured the family home. Zeena al-Hilli was set to return accompanied by an aunt and uncle who travelled to France to bring her home, a source close to the investigation told AFP on condition of anonymity. She and her seven-year-old sister Zainab were the only survivors of an attack that saw her father Saad al-Hilli, mother Ikbal and an elderly female relative gunned down in their car on a forested Alpine road. A passing cyclist was also killed. Her uncle Zaid al-Hilli will face a second day of questioning from investigators, the source added. Zaid presented himself to police in Britain following the murder, denying media reports that the brothers were involved in a financial dispute.British forensics teams began a second day of searches at the family home in Claygate, a quiet, wealthy commuter village some 15 miles (25 kilometres) southwest of London. Saad al-Hilli, a 50-year-old naturalised Briton of Iraqi origin, worked as a mechanical design engineer with the Surrey Satellite Technology firm. The attack on the family\'s car took place outside the village of Chevaline on Wednesday, near the lakeside resort of Annecy in southeast France where the Hillis had been on a camping holiday. Zeena survived the attack by hiding under her dead mother\'s skirt in the backseat and remained motionless inside the vehicle with the corpses for eight hours before police found her. Her elder sister Zainab was shot in the shoulder and beaten around the head, suffering a fractured skull. She remains in a medically-induced coma in a hospital in Grenoble. Police are treating her as a \"key witness\" and hope she can provide some clues once she wakes up. \"The investigators want to speak to her as quickly as possible and with the greatest sensitivity possible,\" prosecutor Eric Maillaud told reporters in Annecy. \"It is out of the question to go and interview her in any sort of rushed way. She is extremely traumatised. Only the doctors have the ability to say (when she can be interviewed) and until I get the green light I will do nothing,\" Maillaud said. He has ruled out getting any information from Zeena. \"All that time she was hiding, terrorised behind her mother\'s legs. She saw nothing,\" he said. Autopsies revealed that each of the four victims was shot twice in the head. \"All four were killed by several bullets and all four were hit twice in the head,\" Maillaud said. \"The whole scene was played out in a very, very short time.\"British and French police began scouring the family home in Claygate for any clues in helping solve the murder on Saturday. Five French investigators led by Colonel Marc de Tarle are in Britain to work on the case, though they did not all visit the house. \"This is an inquiry which is turning out to be long and complex,\" De Tarle said. Maillaud said the search of the home would help to build up a profile of the family, while stressing that there should be no presumption that they were involved in any activity which might have made them targets. French authorities have expanded the area of their search around the scene while police in neighbouring Switzerland and Italy are also helping. In France meantime, investigators were again combing over the scene of the crime after an extensive search for clues by 25 officers on Saturday failed to turn up any new clues, according to Bertrand Francois, a regional police commander. Investigators were also trying to nail down the exact movements of the Hilli family before the murder, he said.