According to the Parisien newspaper, the key suspect in the Lyon explosion case was identified as Mohamed Hichem M., 24, who came to France from Algeria.
French officials have yet to comment on the information.
The suspect, who was arrested on Monday, had been previously unknown to police prior to the 24 May incident, when a blast broke out in the French city of Lyon, injuring 10 people.
"He is in custody. But so far, he refuses to speak," a source close to the investigation told Parisien.
The police questioned the relatives of the detainee — his parents, as well as his younger brother and sister.
Earlier, law enforcement officers had searched his home, where they found the materials needed for the manufacturing of explosives.
On Monday, French police arrested two suspects in connection with the investigation into the Lyon explosion, which took place on 24 May not far from a bakery at the intersection of Victor Hugo Street and Sala Street, near Bellecour Square — one of the city's main tourist attractions.
Following the incident, more than a hundred investigators and technical experts were engaged in the search for the suspect.