Louis Arnaud arrived in Paris on Thursday following his release from Iran, where he was imprisoned for more than 20 months for allegedly taking part in nationwide protests.
Mr Arnaud, who said he was only travelling in the country, was sentenced to five years in prison on security charges and held in Tehran's notorious Evin prison.
He was greeted at Paris-Le-Bourget airport by his family in the presence of French Foreign Affairs Minister Stephane Sejourne.
“Louis Arnaud is free. He will be in France tomorrow after a long incarceration in Iran,” French President Emmanuel Macron said on X late on Wednesday, thanking Oman in particular for its role in obtaining his release.
French media reported that Mr Arnaud, a consultant, 35, was accused of having taken part in nationwide protests sparked by the death of Mahsa Amini, who died after being arrested for allegedly wearing her hijab loosely, violating Iran's strict public dress code for women.
The release is rare positive news concerning the relationship between France and Iran.
Relations have deteriorated in recent months with Tehran holding four French citizens, including Mr Arnaud, in what Paris has said are arbitrary arrests equivalent to state hostage-taking.
France is also increasingly concerned by Iran's regional activities and the advancement of its nuclear programme.
Cecile Kohler, a teacher, and her partner Jacques Paris were arrested in May last year and remain in prison on espionage charges their family denies.
French authorities identified Ms Kohler and Mr Paris as a teachers’ union official and her partner on holiday in the country. Iranian authorities accused them of protesting with Iranian teachers and taking part in an anti-government rally.
The third French national detained in Iran has only been identified by his first name, Olivier.
“This evening, I also think of Cecile, Jacques and Olivier. I am calling on Iran to liberate them without delay,” Mr Macron said.
“I call on Iran to release them without delay.”
Mr Sejourne said on Thursday that France was “still working” for them to be freed.
“Our diplomacy is still mobilised,” he said. “That will be the next victory for tomorrow. But here we must be satisfied with a great diplomatic victory for France.”
Mr Arnaud’s parents, Jean-Michel and Sylvie Arnaud, previously described their son as a “simple citizen of the world”.
Evin prison – in pictures
“Our son is neither a plotter, nor a spy, nor a villain,” they said. “He's a simple citizen of the world, who wants to travel to better know and understand it.”
Mr Arnaud's parents said he had not “taken part in any protest, nor expressed ideas hostile to Iran, its government or Islam”.
Iran has frequently been accused of taking western citizens hostage to use as political bargaining chips.
Rights groups have accused Iran of trying to extract concessions from other countries through such arrests. Iran, which does not recognise dual nationality, denies taking prisoners to gain diplomatic leverage.
