The Europeans still held in Iran
Olivier Grondeau, 34, detained since October 2022 on security charges, arrived in France on Monday after an almost 900-day ordeal, the Elysee Palace and a diplomatic source told AFP.
Human rights groups say those still in custody are being kept by Iran for use as bargaining chips in negotiations with foreign governments.
The known prisoners may not include all those held, with many of those detained advised by their foreign ministries not to publicise cases in the hope they can be resolved behind the scenes.
Around twenty Westerners are held in Iran, a French diplomatic source, asking not to be named, told AFP on Thursday.
Here are the known prisoners:
Britain
British-Iranian activist Mehran Raoof was arrested in October 2020 on national security charges and sentenced to 10 years and eight months in jail, according to Amnesty International.
He was held for months in solitary confinement in Tehran's notorious Evin prison, where he managed to smuggle out a letter last year complaining of harsh treatment of dual nationals, Amnesty said.
In February 2025 Iran charged the detained British couple Craig and Lindsay Foreman with espionage, accusing them of collaborating with Western intelligence services.
The BBC has reported the couple are in their early 50s and were on a motorbike trip around the world when they were detained in January.
Nasrin Roshan, an Iranian-British dual national, is currently serving a three-year prison sentence in Evin Prison after being convicted on national security charges.
She was arrested on November 16, 2023 at Tehran's international airport while attempting to leave Iran. The Human Rights Activists News Agency (HRANA) said in March she was hospitalised after losing consciousness.
France
French teachers' union official Cecile Kohler and her partner, Jacques Paris, were detained in May 2022 while sightseeing in Iran. They are accused of spying.
Kohler's sister Neomie has warned about the health of the pair warning they risk dying if they are not released.
Sweden
Iranian academic Ahmadreza Djalali, a resident of Sweden, was arrested during a visit to Iran in April 2016 and sentenced to death in 2017 on charges of spying for Israel's Mossad.
He was granted Swedish citizenship while in jail. His hanging was postponed but his family says he remains on death row.
In March, Stockholm called for his immediate release on humanitarian grounds after receiving information on the deterioration of his health.
The Swedish foreign ministry has also confirmed that Iran is holding another Swedish man, who is in his twenties and was arrested in January 2024.
Swedish media reported that this man was the target of an international arrest warrant in connection with a deadly shootout in Sweden.