The daughter of a British-US national detained by Iran has urged the UK Government to do “whatever they have to do” to make her family “whole again”.

Wildlife conservationist Morad Tahbaz, 66, was taken back into custody after being allowed out on furlough last week on the day charity worker Nazanin Zaghari-Ratcliffe and retired civil engineer Anoosheh Ashoori were released. Mr Tahbaz’s family says he has gone on hunger strike.

His daughter Roxanne is calling for him to be returned to the UK, along with her mother, who she says is under a travel ban in Iran.

Asked what she wants UK officials to do, she said: “We just want them to do whatever they have to do to bring them back.

“I’m not a politician so I can’t really advise them on what they can or can’t do to do that. But we just want our family to be whole again.”

Ms Tahbaz said she had not spoken to the Foreign Secretary personally, but “we do have people in our family that (have) been working very fervently to get answers, and I know that she’s been in touch with them”.

Asked about the reunion of Ms Zaghari-Ratcliffe and her family in the UK, Ms Tahbaz said “it does trigger something for us”.

“I mean, Nazanin’s family’s been really kind and wonderful to us, so we are genuinely happy for them,” she said.

“But obviously it does trigger something for us and it’s very, very devastating that we’re in this position. But we look at their family and their joy, and hope that we’ll have a very similar experience very soon.

“I think it’s very clear that it’s incredibly urgent at this stage, and the bottom line is we want them home.”

Ms Zaghari-Ratcliffe, speaking in public for the first time since being released, told a press conference earlier that without the release of other dual nationals in Iran, “the meaning of freedom is never going to be complete”.

She told reporters at Portcullis House: “I believe that the meaning of freedom is never going to be complete as to such time that all of us who are unjustly detained in Iran are reunited with our families.

“To begin with Morad, but also the other dual nationals, members of religious groups, or prisoners of conscience who are… I mean, we do realise that if I have been in prison for six years there are so many other people, we don’t know their names, who have been suffering in prison in Iran.”

Last week, the UK said it had secured Mr Tahbaz’s furlough, along with the release and return of the two other dual nationals.

This came after the UK Government finally agreed to settle a £400 million debt to Iran dating back to the rule of the Shah in the 1970s.

But two days later Mr Tahbaz was forced to return to Evin Prison.

The Foreign, Commonwealth and Development Office told the PA news agency that Mr Tahbaz had since been moved to a residential location in Tehran, but Ms Tahbaz said he had been returned to the prison on Monday morning.

Downing Street said on Monday that the Government was continuing to lobby Iranian authorities for Mr Tahbaz’s return.

The Prime Minister’s official spokesman said the UK was working very closely with the US on the issue.

He said: “He is a tri-national. We are working very closely with the United States to secure his permanent release and departure from Iran.

“We have been in regular contact with Morad’s family and continue to lobby the Iranian authorities at the highest level.”

Mr Tahbaz was arrested during a crackdown on environmental activists in January 2018.

He is a prominent conservationist and board member of the Persian Wildlife Heritage Foundation, which seeks to protect endangered species.

He was sentenced to 10 years in prison with his colleagues on vague charges of spying for the US and undermining Iran’s security.