The daughter of a British-US national detained by Iran has staged a demonstration outside the Foreign Office urging the UK Government to bring her father home.

Wildlife conservationist Morad Tahbaz, 66, was returned to custody after being allowed out on furlough last month, on the day charity worker Nazanin Zaghari-Ratcliffe and retired civil engineer Anoosheh Ashoori were freed.

His daughter Roxanne said her family was led to believe that he would be included in any deal negotiated at the time, alongside the two dual nationals.

But she said they felt abandoned by the UK Government, with her father now back in prison.

Ms Tahbaz said her mother had also been placed under a travel ban by the Iranian authorities.

Speaking at her protest outside the Foreign, Commonwealth and Development Office (FCDO) on Wednesday morning, she told the PA news agency: “We’re here today because it’s been one month since Nazanin and Anoosheh have come home, and my father’s still sitting in prison and my mother’s still on a travel ban.

“So we’re hoping to have the press and the media help us to call on the Government and on the Foreign Secretary (Liz) Truss to keep her promise and bring him home to us, so we can be reunited as a family.”

In March, the UK said it had secured Mr Tahbaz’s furlough, along with the release and return of Mrs Zaghari-Ratcliffe and Mr Ashoori.

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.

I'd be happy to forego the apology if they brought my parents home. It's really about action at this point, instead of just words

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

The FCDO had said he was moved to a residential location in Tehran but Ms Tahbaz said he was taken back to the prison shortly afterwards.

On what steps the UK Government should take next, she told PA: “We want them to follow through on the promise they made to us – we were always led to believe over the past four-plus years that he was to be a part of any deal they were making, and we were led to believe he’d be coming home as part of that.”

Asked if she would like the Government to apologise after she said it misled her family over her father’s fate, she said: “I’d be happy to forego the apology if they brought my parents home. It’s really about action at this point, instead of just words.”

We've pleaded and begged and been very vocal about wanting them to keep their promise, and it's been four weeks, and nothing has changed for us as a family

Ms Tahbaz said she has not spoken to Ms Truss personally but there is a nominated member of her family dealing with the FCDO.

She said she does not “see the point” in sitting down with the Foreign Secretary “unless she’s going to give me an actual update”.

“We’ve pleaded and begged and been very vocal about wanting them to keep their promise, and it’s been four weeks, and nothing has changed for us as a family,” she said.

“And so unless the meeting is to discuss next steps and what actually may happen, or what we can expect, then I don’t think that it would help really.”

Mr Tahbaz, who also has Iranian citizenship, 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.

Ms Tahbaz said “all we can do is stay positive” because “our parents are counting on us to bring them home”.

Asked when she last had contact with her father, she said: “Not for some time now, actually. We don’t have direct contact – it’s only on speakerphone through my mum, with another speakerphone.

“So we kind of shout across to hopefully be able to at least convey to him that he’s not alone and that we’re still waiting for him and that we love and miss him.”

On how Mr Tahbaz feels about the UK Government’s response to his situation, she said: “I think he’s made it very clear that he feels abandoned, and that’s why I’m here today – to make sure that he’s no longer left behind.”

An FCDO spokesperson said: “The Iranian government committed to releasing Morad from prison on an indefinite furlough. Iran has failed to honour that commitment.

“Continuing his horrendous ordeal sends a clear message to the international community that Iran does not honour its commitments. We continue to urge the Iranian authorities at every opportunity to release him immediately.”