Den samme 16-åringen som kirke-jihadisten Adel Kermiche forsøkte å reise til Syria med i fjor, via Sveits, ble igjen arrestert i Sveits bare dager før Kermiche gikk til aksjon.
Har ikke fransk politi noe kontroll? spør man seg.
The 17-year-old tried to travel to Syria last year with Adel Kermiche, French and Swiss media say.
The unnamed teenager was reportedly arrested in Geneva earlier this month and handed over to French authorities.
The news of the detention of a close friend of Kermiche, who pledged allegiance to the Islamic State group in a video, comes at a time when French intelligence services are under close scrutiny.
Reports in Le Parisien and the Tribune de Geneve newspapers said it was not known why the 17-year-old, from northern France, went to Geneva earlier this month.
He had already tried to fly with Kermiche to Syria via Switzerland last year. Both were turned back from Turkey.
In the latest development, Swiss security services picked up the teenager, and another friend, on 20 July and handed them over to French authorities.
A source told AFP news agency that «nothing suggests he was in any way implicated» in the church attack on 26 July.
Frankrike tåler ikke lenger flere slike dementier.
Kermiche var en jihadist som bare ventet på å angripe, likevel fikk han være uten elektronisk fotlenke fire timer hver dag. Når den var av så ikke myndighetene hvor han befant seg.
Den andre kirketerroristen hadde et annet familienavn som nå er kommet frem: Han heter Abdel Malik Petitjean.