Morad Tahbaz, an environmental campaigner with UK and US citizenship, has been temporarily released from jail in Iran but London has "unfinished" business to secure his real freedom, his daughter said on Wednesday.
Tahbaz, 69, who has Iranian citizenship as well, is currently at his family home in Tehran after being released from Evin prison on temporary furlough with an ankle monitoring bracelet, Roxanne Tahbaz confirmed.
He remained behind in the Tehran jail when British-Iranians Nazanin Zaghari-Ratcliffe and Anoosheh Ashoori flew home in March, after the UK government repaid a historical debt to Tehran.
Roxanne has accused the UK government of abandoning her father, claiming it led the family to believe that he would be included in any deal to free Zaghari-Ratcliffe and Ashoori.
Following news of his temporary furlough, she said she was glad he could now be with her mother in the Iranian capital, as well as receive the medical attention that he "urgently needs".
"However, the UK government's work is unfinished," Roxanne added in a statement.
"My father is a UK-born national and he and my mother should have been on the flight with Nazanin and Anoosheh four months ago. They should be free. Home is not in Iran, home is with their children."
She noted British Foreign Secretary Liz Truss is running to replace Boris Johnson as Conservative leader and prime minister, and has been touting her record of delivering on policy pledges.
"I hope she will stand by her promise to my family and to my father and ensure his unconditional release."
The UK government maintains that it cannot secure his release alone because he is also a US citizen, and that the Iranians are also having discussions with US officials.
"Morad is a tri-national and we continue to work closely with the United States to urge the Iranian authorities to permanently release him and allow his departure from Iran," the foreign ministry in London said.
A Tehran court in 2020 jailed Tahbaz for 10 years on charges of spying, conspiring with Washington and damaging national security.
He and seven others convicted on similar charges worked with environmental group Persian Wildlife Heritage Foundation to track endangered species.
They were arrested on suspicion of espionage in early 2018.
Britain's foreign ministry told Tahbaz's family that when the others were released in March, Iran had agreed to free Tahbaz on unrestricted curfew.
But he was returned to Tehran's Evin prison within 24 hours of his partial release, prompting him to go on hunger strike.
There was no immediate comment from Iranian authorities Wednesday.
Zaghari-Ratcliffe was released on furlough in March 2020 but was taken back to Evin prison after two weeks, before being fully released two years later.