Detectives investigating the death of a Claygate businessman and two members of his family are looking into whether his wife had a secret ex-husband.
Saad Al-Hilli, 50, of Oaken Lane, his wife Iqbal, 47, and her mother, Suhaila al-Allaf, were shot dead in the family’s BMW in the French Alps near Lake Annecy on September 5, 2012.
The family’s two daughters, Zainab, then seven, and Zeena, then four, survived the attack. A French cyclist was also shot dead.
Police are now said to be exploring whether Mrs Al-Hilli had a secret ex-husband who died in "mysterious circumstances" in America on the same day as the shootings.
Benoit Vinnemann, one of the most senior police commanders working on the case, said he believes Mrs Al-Hilli was "secretly married" to an American dentist, named only as James T, between February 1999 and December 2000.
Lt Col Vinnemann said James T died of a heart attack on the same day the family were murdered but that they "still haven’t had a response to certain questions."
It has also emerged in national media today that a suspected Iraqi contract killer was arrested in connection with the Alps shootings.
The Daily Mail reported today investigators took a 35-year-old convicted criminal into custody last month and questioned him for three days.
Annecy prosecutor, Eric Maillaud, said the man was investigated following a "specific claim from another prisoner that he could have been involved in a contract to kill Iraqis".
But the man was released after giving an alibi and Mr Maillaud said they could not establish a link with the Al-Hilli family.
The unnamed man is the third person to be arrested in connection with the murders.
Mr Al-Hilli's brother, Zaid, of North Parade, Chessington, and a former French police office were both arrested in relation to the murders but were released without charge.