Father sings Happy Birthday to toddler daughter trapped in Iran after her mother is detained without charge

Richard Ratcliffe says his wife Nazanin had never been in trouble with the Iranian authorities before her arrest in April

Nazanin and her daughter Gabriella are trapped in Iran after Nazanin was detained without charge by the Iranian authorities (Change.org)

The British father of a toddler trapped in Iran without her parents has sung Happy Birthday to her via Skype and left a card and balloons for her at the Iranian embassy.

Richard Ratcliffe’s daughter Gabriella is currently staying with grandparents in Iran as she is unable to return to the UK without her mother to take her home.

Her mother, Nazanin Zaghari-Ratcliffe, was arrested on 3 April at an airport in Iran after visiting her family with her daughter and has been held in solitary confinement due to an unspecified issue of “national security”.

Mr Radcliffe, who is from north London, said his wife had been detained “without charge” by the Iranian Revolutionary Guard as she planned to fly back to London and was taken to an unknown location in Kerman Province, around 621 miles south of the capital Tehran.

He said she had been forced to sign a confession “under duress” despite not knowing what she was accused of, and it was three days before she was allowed to telephone her family to tell them what was going on.

Gabriella - who is a British citizen - is currently being cared for by grandparents, but has had her passport confiscated and can only leave the country if accompanied by her mother or father according to Iranian law.

Mr Ratcliffe has been advised not to go to Iran for his own safety.

Mr Ratcliffe with his wife and daughter. Nazanin has travelled in the country without problems in the past (Family Handout)

Speaking to his daughter via Skype outside the Iranian embassy he used her birthday to issue a fresh plea for the return of Nazanin and Gabriella.

A Change.org petition organised by the Free Nazanin campaign has gathered more than 760,000 signatures since its launch and urges David Cameron to intervene.

Mr Ratcliffe also tried to present a card and balloons to the embassy, asking them to pass it onto his daughter.

Ms Zaghari-Ratcliffe, who works as a project-coordinator for the Thomson Reuters Foundation, has travelled in the country before without incident and her husband does not believe they was anything in her work or personal background which should provoke the suspicions of the Iranian authorities.

Mr Ratcliffe said he was going against the advice of the Foreign Office by speaking out because he hoped to could use public pressure to secure her release.

He said support from the public was “really really powerful” and helped him keep going.

"I look at all these lovely comments, and some of them are so beautiful they'll bring tears to my eyes: the energy and the love and the kindness that's out there.

"Today is quite a happy day. Her birthday is tomorrow - and that will be a sad day.

"Sometimes you speak to Gabriella and she just gets really upset and keeps asking for her mum, which is the most heartbreaking part."

A Foreign Office spokeswoman told the BBC: "We have been providing support to the family of a British-Iranian national since we were first informed of her arrest, and will continue to do so."

Additional reporting by PA