A second man is being held by French police investigating the murder of a Claygate family.
But prosecutors also said they could not demonstrate a direct link between the killing of the Al-Hillis and the two men they have held.
Saad Al-Hilli, 50, was found shot to death in his car with his wife Iqbal and her mother, while a French cyclist was also found shot dead nearby.
The two Al-Hilli children, both former pupils of Claygate School, survived the attack.
Zainab, then seven, was shot and pistol whipped by the gunman but survived the attack and Zeena, then four, escaped unharmed after she hid beneath her mother’s skirt.
Attention has turned to Mr Mollier as the possible intended target since Saad's brother, Zaid Al-Hilli, who lives in Chessington, was released from police bail.
A police search of a house in the town of Talloires, about 10km from the murder scene in Lake Annecy, uncovered weapons and a motorbike was said to have been seized.