The man was treated by a fire brigade on Monday when he suffered serious burns following an explosion, the prosecutor's office said on Wednesday.
Products and materials intended to manufacture explosive devices have been found at his hotel room, it said.
France is on maximum threat alert with less than two months to go until the start of the Paris Olympics.
Last month, French security services foiled the first planned attack on the Games, with the arrest of an 18-year-old Chechen man allegedly preparing a suicide mission at Saint-Etienne's soccer stadium.
[
add
]
[
|
|
...
]