Zeena al Hilli was accompanied by an aunt and uncle, a source close to the investigation said 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. A passing cyclist was also killed.
Zeena’s return came amid media speculation that police were looking at Mr al Hilli’s work on a secret contract for one of Britain’s biggest defence companies as a possible motive for the killings. Mr al Hilli, a 50-year-old naturalised Briton of Iraqi origin, worked as a design engineer with the Surrey Satellite Technology firm.
Saad’s brother Zaid al Hilli faced a second day of questioning yesterday. He had presented himself to police in Britain following the murder, denying reports the brothers were involved in a financial dispute.
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. Autopsies revealed each victim was shot twice in the head.
Zeena survived by hiding under her dead mother’s skirt in the back seat and remained motionless 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 came out of a medically-induced coma in a hospital in Grenoble.
Police are treating her as a “key witness”.
“The investigators want to speak to her as quickly as possible and with the greatest sensitivity possible,” said prosecutor Eric Maillaud. “She is extremely traumatised. Only the doctors have the ability to say [when she can be interviewed].”
He has ruled out getting information from Zeena.
British forensics teams began a second day of searches at the family home in Claygate, a quiet, wealthy commuter village 25km south-west of London.
Five French investigators are in Britain to work on the case, though they did not all participate in the search of the al Hilli home.
Maillaud said it should not be presumed the family were involved in any activity which might have made them targets.
French authorities have expanded their search around the scene of the massacre. Swiss and Italian police are also helping. Twenty-five officers combed the area on Saturday, but did not turn up any new clues.