British media reports say police have arrested the brother of a British-Iraqi man slain with three other people in a remote area of the French Alps.
The media identified the man arrested on suspicion of conspiracy to commit murder as Zaid al-Hilli.
When asked about al-Hilli, police said Monday that a 54-year-old man had been arrested.
The force did not mention al-Hilli by name - authorities in Britain rarely identify suspects who have not been charged - but such statements are routinely understood as confirmation of media reports.
In September last year Saad al-Hilli, 50, was gunned down with wife Iqbal, 47, and her mother, Suhalia, 74, in their BMW while they were on holiday near Lake Annecy in France.
French cyclist Sylvain Mollier, 45, was also shot dead.
The al-Hillis' two young daughters survived.
Family friends have described a dispute between Zaid al-Hilli and his brother Saad al-Hilli over their father's estate.