The voice in an audio recording of the Islamic State group statement claiming the Paris attacks belonged to a French convert to Islam named Fabien Clain, a source close to the investigation said Tuesday.
The 35-year-old, a veteran of radical Islamist networks in the southern French city of Toulouse, is now in Syria where he has joined IS, the source told AFP.
He was close to Mohamed Merah, who shot dead seven people, including three Jewish children, in Toulouse in 2012.
Clain, who goes by the alias Omar, was convicted in 2009 of recruiting jihadists and sentenced to five years in prison, after which he left for Syria.
Clain and his brother Jean-Michel, originally from the French overseas territory of La Reunion, are converts to Islam who were radicalised in the early 2000s.
They became close to a Frenchman of Syrian origin in the Toulouse area, Olivier Corel, dubbed the "white imam", whom they consider their spiritual guide.
Fabien Clain was considered one of the organisers of a network sending Islamist recruits to fight US soldiers in Iraq.
In April this year Le Monde daily revealed that Clain was suspected of instigating a foiled attack on a church in a southern Paris suburb.
The attack was thwarted when the assailant, Algerian student Sid Ahmed Ghlam, accidentally shot himself in the leg.
After Friday's killing spree in Paris by gunmen and suicide bombers targeting a concert hall, bars, restaurants and the national stadium left at least 129 dead, the Islamic State group audio claimed responsibility.
In the audio, Clain's triumphant voice says "eight brothers wearing explosive belts and carrying assault rifles" conducted a "blessed attack on... Crusader France."
It said the targets of the attacks "were carefully chosen", including the Bataclan concert hall "where hundreds of idol worshippers were gathered".
The recording incorrectly names the 18th arrondissement of Paris as one of the locations targeted.
No attacks occurred in the northern district, but a car that had been rented by a suspected eighth attacker, named as Salah Abdeslam, was found there early Tuesday.
Seven jihadists blew themselves up or were killed by security forces, while an international arrest warrant has been issued for Abdeslam.
The propaganda statement also made reference to French air strikes on IS positions in Syria.
It said France was guilty of "striking Muslims in the caliphate with their aircraft" and threatened further attacks "as long as it continues its Crusader campaign".
"This attack is just the beginning of the storm," it said.