Iran has transferred five Iranian-Americans from prison to house arrest, part of a possible deal over billions of dollars of Iranian assets frozen in South Korea.

Three of the five prisoners have been previously identified while two others have not been named publicly. Those identified include:

Siamak Namazi, an energy executive, was arrested in 2015. He had been an advocate of closer ties between Iran and the West.

Iran sentenced both Namazi and his father, Baquer Namazi, to 10 years in the country’s notorious Evin Prison on what the U.S. and U.N. say are trumped-up spying charges.

Baquer was placed under house arrest for medical reasons in 2018 but prevented from leaving Iran despite his family’s pleas that he travel to receive emergency heart surgery after suffering multiple hospitalizations. He ultimately left Iran in October 2022.

Siamak is the longest-held Iranian-American held in Tehran. He appealed to President Joe Biden in an essay in The New York Times in June 2022 as American and Iranian nuclear negotiators met for indirect talks in Doha, Qatar, demanding he intervene to “end this nightmare.”

The murky espionage charges against Iranian-American businessman Emad Sharghi came to light in early 2021, when an Iranian court announced that the venture capitalist had been sentenced in absentia to 10 years in prison.

His family says Iran had cleared him of spying charges in December 2019 after jailing and interrogating him for months. Iran says security forces then caught Sharghi on the country’s northwestern border and re-arrested him as he tried to flee Iran while free on bail.

Morad Tahbaz, a British-American conservationist of Iranian descent, was meant to be released from prison on furlough as part of Iran’s deal with the U.K. to resolve a long-running debt dispute in March 2022.

That agreement freed two high-profile detainees, charity worker Nazanin Zaghari-Ratcliffe and retired civil engineer Anoosheh Ashoori, who flew home to London. But Tahbaz remained stuck in Iran. Reports soon emerged that he was sent back to prison despite the furlough promise.

Tahbaz was caught in a dragnet targeting environmental activists while visiting Iran in January 2018 and sentenced to 10 years in prison.