Police are currently searching the house of the man arrested as part of the investigation into the deaths of four people in 2012, in village near Chevaline.
The French prosecutor has said the man is not a suspect at this time but is being questioned because he resembles an e-fit and was in the area at the time of the killings. He could be released as early as this evening.
More top news
Prisons hit record highs for the number of inmates released in error, as well as for the number of assaults on both prisoners and staff.
One person was killed and several others injured when a fairground ride malfunctioned and broke apart mid-swing.
The government has faced questions as to why the expert analysis of one of the central issues of Brexit was not ordered sooner.