UK police have been searching the home of the British-Iraqi al-Hilli family, whose members were gunned down in a village close to Lake Annecy last Thursday.

The bomb squad has been called in, neighbours have been evacuated and the area surrounding the house cordonned off.

The brother of murdered man Saad al-Hilli has come forward to say there was no family feud, although a letter has emerged in which Saad accuses his brother Zaid of being a "control freak".

Police are also looking at whether Saad al-Hilli's job mapping satellites for one of Europe's biggest defence companies had something to do with the killings. He was apparently working on a secret contract.

Governments have been known to make killings appear gangland related, according to security analyst Sally Leivesley: "If this is organised crime, then we look at state-sponsored terrorism because we've certainly seen links between Iran and organised crime, and organised crime provides denialbility if it's a state situation.

"But equally, forensically, it could be mischance. You know, we are looking at very, very broad options, perhaps 20 or 30 different permutations in this one."

There is hope that seven-year-old survivor Zainab will be able to shed light on what happened now that she is conscious, but she will also discover that her mother and father were killed in the attack.