London (CNN) -- A British bomb disposal unit investigated suspicious items found at the home of a couple who were killed in an apparent execution-style shooting in France last week, police said Monday.
Police threw up a cordon around the home of Saad and Ikbal al-Hilli, who were killed along with Ikbal al-Hilli's 74-year-old mother in the French Alps. The al-Hillis' two daughters survived, one with wounds from a beating and a gunshot.
Officers sent residents away from their houses around the al-Hilli home in Claygate, Surrey, a wealthy town outside of London, police in Surrey County said.
But the items investigated by the bomb squad were not dangerous, and residents of the area were allowed to return, police said several hours later.
Last week's attack on the al-Hilli family was, in the words of one French prosecutor, an "unheard-of savagery."
A French cyclist, Sylvain Mollier, was killed alongside the British-Iraqi family members Wednesday on the outskirts of Chevaline, an Alpine village popular with outdoor enthusiasts.
Each victim had two gunshot wounds to the head.
The couple's 7-year-old daughter was badly beaten and shot. Their 4-year-old daughter hid for hours behind her dead mother's legs.
French authorities plan to question the elder girl, named in media reports as Zainab, when she is in "a fit mental state," prosecutor Eric Maillaud said Monday.
The girl is also being protected by police in case of a further threat to her safety. She suffered head wounds and a gunshot wound to the shoulder, but came out of a medically induced coma Sunday, the French prosecutor's office said.
The 4-year-old, identified in media reports as Zeena, has not given investigators any information about who carried out the attack.
She is physically unharmed and will be returned to Britain, French prosecutors said Sunday. She has been under the care of French doctors, watched over by police and British consular officials.
The Surrey County Council refused confirm to whether she came home over the weekend, citing the safety of the children.
French and British authorities are still trying to determine who killed the four people and why.
Was it a robbery gone bad? A family feud over inheritance? A case of mistaken identity? Or, maybe, one of being at the wrong place at the wrong time?
Theories have abounded since investigators found the bodies.
About 25 shots were fired, police said.
Authorities have been tight-lipped about possible perpetrators and motives, even as the investigation stretched Monday from France to Britain and they asked Italian and Swiss officials for help.
One clue may lie in a report by a cyclist who said he saw a green 4x4 vehicle and a motorbike near the site of the killings.
That cyclist, identified as a former member of the Royal Air Force in media reports, discovered the bodies at the rest stop. The engine of the al-Hillis' car was still running, according to authorities.
The al-Hilli family arrived in France in late August for a camping holiday, prosecutor Maillaud said.
Saad al-Hilli was an Iraqi-born engineer who lived south of London with his wife and two daughters.
He was born in 1962 and was a naturalized British citizen. He worked at Surrey Satellite Technology, a high-tech company owned by EADS, an aerospace corporation that builds satellites.
Neighbor Jack Saltman, in al-Hilli's well-heeled Surrey County community of Claygate, said al-Hilli came from Iraq "many years" ago.
Police plan to question al-Hilli family members, including his brother, Maillaud said.
The prosecutor downplayed reports of a conflict between the brothers over an inheritance.
The unnamed brother went to police voluntarily after he learned of the deaths, Maillaud said. He returned the next day on his own accord to tell police there had been no conflict with al-Hilli over money.
Investigators have not ruled out the possibility that the al-Hillis were killed in a robbery at the rest stop, and that the cyclist may have been killed after stumbling upon the robbery.
The bodies will be released to their families for burial as soon as judicial authorities conclude they are no longer necessary for the inquiry, the prosecutor said.
CNN's Stephanie Halasz, Saskya Vandoorne, Pierre Meilhan, Dan Rivers and Per Nyberg contributed to this report.