The 14-year-old had been locked in a cellar in the area without light, food or a toilet for a night on Monday last week.
His kidnappers threatened him with burgling his family’s house if he didn’t give them €150.
Scared that his kidnappers would carry out their threats, the boy didn’t return home until Wednesday, staying at a friend’s house on Tuesday night.
The kidnappers’ motive is still unknown, but the boy’s mother claims the kidnapping is linked to an incident at Pontoise train station last Sunday, during which a group of boys took her son’s phone.
“They promised him they would give it back when they met up the next day, then they took the phone,” the boy’s mother told Le Parisien.
“This time they didn’t beat him up, but what happens next time?”
The boy is currently staying away from the family home to avoid a repeat.
Police have confirmed they have launched an investigation to find out who the kidnappers are.