This is what President Emmanuel Macron says in a statement.
Olivier Grondeau, who has now been released, was arrested in October 2022, accused of espionage. He was sentenced to five years in prison, but both he and the French government deny the allegations.
A non-named French citizen, who has been under house arrest for four months, has also been released and is now in France.
French Foreign Minister Jean-Noël Barrot tells TV channel TF1 that France has not given Iran anything in exchange for releasing Grondeau. Iran has not commented on the release.
The release comes after France and several other European countries have been trying to resume nuclear energy talks with Iran.
