French citizen Louis Arnaud held in Iran arrives in Paris

Emerging from a small plane at Le Bourget airport outside Paris, a visibly tired but smiling Arnaud shook hands with Foreign Minister Stephane Sejourne before embracing his parents, according to images aired on television.

Arnaud linked arms with his relatives as they entered a private room at the airport out of view of the cameras.

"I am very glad to welcome one of our hostages who was indeed held arbitrarily in Iran," Sejourne said.

"Our diplomatic service is still at work" to free three other French citizens: Jacques Paris, Cecile Koller and a man named only as Olivier held in Iranian jails, he added.

Arnaud, a 36-year-old consultant, set off in July 2022 on a round-the-world trip that led him to Iran.

It was "a country he had long dreamed of visiting for the richness of its history and its welcoming people," his mother Sylvie said several months ago.

But he was arrested in September 2022 with other Europeans accused of joining demonstrations over the death of Mahsa Amini, a 22-year-old Iranian Kurd who died after her arrest by the morality police in Tehran for allegedly breaching the Islamic republic's strict dress code for women.

While Arnaud's travelling companions were soon released, he was kept in prison before his November sentencing for propaganda and harming Iranian state security.

Frenchman Benjamin Briere and French-Irish dual national Bernard Phelan were freed by Iran in May 2023 for "humanitarian reasons".

Both had been severely weakened by a hunger strike.

Tehran, which holds around a dozen Western citizens, is accused by their supporters and rights groups of using the prisoners as bargaining chip in international negotiations.