Fyra ihjälskjutna i brittisk bil vid fransk sjö (2012-09-05)

Saad al-Hilli and his brother Zaid jointly owned the home in Claygate, Surrey, where Saad lived with his family.

Saad told friends his brother wanted the money for his share of the house - approximately £400,000.

Investigators in France and the UK have been examining Saad al-Hilli's business interests. He worked as a mechanical engineer at Surrey Satellite Technology, which makes satellites for emerging democracies.

The company was recently bought by defence giant EADS, which has raised questions among conspiracy theorists that Saad al-Hilli's murder was work-related.

Gary Aked, who first met Saad in the early 1990s when they worked together, does not believe his work would have put him in any danger.

"He wanted to work on engineering projects without the politics that went on in some defence areas," he says.

"He has never worked at any other company that I know of that has given him sensitive work to do."

Investigators are also examining Mr al-Hilli's connections to Iraq where he was born - he came to Britain in the 1970s. Fellow engineer James Mathews says Saad was last in Iraq two years ago.

"They had a family house in Baghdad, but I think that had been sold as a building plot because it wasn't worth going back there for. I think they got rid of that and that was Saad's last tie with Iraq."

French police are continuing to follow multiple lines of enquiry and the French prosecutor leading the case has warned that it could take years to solve.