Police in France believe whoever shot dead three members of a British family in the Alps a year ago may have been an experienced gunman who had killed before.
Saad al-Hilli and his wife Iqbal, from Claygate, her mother Suhaila al-Allaf and Sylvain Mollier, a French cyclist, were shot on 5 September 2012. They were on holiday by Lake Annecy.
Mr and Mrs al-Hilli's daughters survived the shooting on a remote forest road in Chevaline.
Mr al-Hilli's brother Zaid, who is from Chessington, Surrey, is under arrest on suspicion of conspiracy to murder amid claims he doctored documents to ensure he inherited the family estate following the death of their father.
The BBC reports he has always denied any involvement in the killings.
But police said on Friday they believe their chief line of inquiry remains a row over the inheritance.
"This is being followed up actively," said Annecy prosecutor Eric Maillaud.
A BBC correspondent reported that the police are "saying Zaid... is not the number one suspect.
Police were also now "pretty sure" there was no connection with the murdered cyclist.