A dozen Western passport holders remain detained in Iran, even after the release on Monday of five US citizens in a swap deal with Tehran.

Rights groups say those held are innocent of any crime and are being held as part of a deliberate policy of hostage-taking by Iran to extract concessions from foreign governments.

Earlier, the five Americans including Siamak Namazi, a businessman held since 2015, were released by Tehran and were flying home via Doha. The deal also sees the release of five Iranians held by the United States and the unfreezing of Iranian funds totalling $6 billion by US ally South Korea.

Tehran insists all the foreigners held have been subject to proper judicial process. Activists fear there may be more cases, as governments usually advise families not to publicise arrests in the hope a solution can be found without publicity.

- Britain -

British-Iranian labour rights activist Mehran Raoof was arrested in October 2020 and is being held in solitary confinement, Amnesty International says.

- Germany -

German-Iranian Nahid Taghavi, in her late 60s, was sentenced to 10 years and eight months in jail in August 2021 after being arrested at her Tehran apartment in October 2020. She is held in Evin prison.

Jamshid Sharmahd, a German citizen, was captured by Iran in August 2020 while travelling through the UAE, according to his family. He was charged with terrorism over a lethal 2008 bombing. His family have rubbished the accusations.

A US resident, he was sentenced to death in February, a verdict that has been upheld by the supreme court. His family fears he could be executed any day.

- 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.

Banking consultant Louis Arnaud was arrested in September 2022 while visiting Iran. Described as a passionate traveller, he is jailed in Evin prison in "extremely harsh" detention conditions, according to his parents.

Another French citizen is confirmed by Paris to be held but their identity has never been revealed.

French-Iranian academic Fariba Adelkhah was released earlier this year but is still unable to leave the country.

- Austria -

Iran in June released two Austrian citizens held for several years but a third Austrian, who has not been named, was sentenced earlier this year to seven and a half years in jail in Iran for spying, according to Vienna.

- 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.

Habib Chaab, an Iranian-Swedish dissident, disappeared during a visit to Turkey in October 2020.

He turned up in Iran accused of being a leading figure in an Arab separatist group and of perpetrating bomb attacks. He was sentenced to death and executed on May 6.

Sweden and the European Union this month said Johan Floderus, 33, who works for the EU diplomatic service, was arrested in April 2022 at Tehran's airport as he was returning home from a trip with friends.

His detention was not officially disclosed until it was first reported by the New York Times this September.

- Spain -

Spanish citizen and football fan Santiago Sanchez Cogedor has been in detention in Iran since October. He was arrested while trying to walk to Qatar for the football World Cup.

- United States -

According to Washington, the release of the five US citizens on Monday means there are no more US nationals detained in Iran.

However the family of Virginia-based Iranian Shahab Dalili, who was arrested in 2016 while visiting Tehran, has expressed dismay that the US resident was not included in the swap, as have the family of Jamshid Sharmahd.

Meanwhile former FBI agent Robert Levinson vanished in 2007 on a trip to Iran. The US has accused Iran of abducting and detaining him and being responsible for his "probable" death.