The third and as-yet unnamed man who attacked the Bataclan concert hall in Paris on November 13 went to Syria with a group of other young people at the end of 2013, a judicial source said on Wednesday.
Confirming a report in Le Parisien newspaper, the source did not give any further details, but according to the daily newspaper, the group was from the eastern city of Strasbourg and came back in the spring of 2014.
Seven of them, not including the Nov. 13 bomber, were later arrested and jailed, the report said.
The Bataclan shootings were part of a co-ordinated attack that killed 130 people in Paris and which was claimed by Islamic State, the militant group that now controls large parts of Syria and Iraq.
The other two attackers at the Bataclan, among seven who died in the assaults, have been named as Samy Amimour, 28, from Drancy, north east of Paris, and Ismail Omar Mostefai, 29, who lived in Chartres, south west of Paris.