The Iranian Revolutionary Guard accused a British-Iranian aid worker who has been detained since early April of trying to “overthrow” the government in a statement released earlier today.

Nazanin Zaghari-Ratcliffe, who has dual British-Iranian nationality, was detained by the Iranian Revolutionary Guard on 3 April at an airport as she tried to return to the UK.

The 37-year-old is being held in  the notorious Evin prison in Tehran – the same prison British-Iranian Ghoncheh Ghavami was held in after she was arrested for attending a volleyball match.

Nazanin is a project manager for Thomson Reuters Foundation, a charity that does not work in Iran.

Her husband Richard is who is campaigning for her release has a petition on Change.org which currently has more than 764,000 signatures.

Jailed: Nazanin Ratcliffe was separated from her daughter Gabriella and arrested at the airport as the pair tried to return to the UK after a holiday

The statement from the Iranian Revolutionary Guard released in Farsi and translated to Richard claimed: ‘Nazanin was one of the ring leaders in efforts planning the overthrow of the Islamic regime through projects involving the media and social media, working under the direction of media companies and espionage networks belonging to foreign governments.’

Richard told Change.org: ‘This is both extraordinary and untrue. Nazanin was in Iran on a family visit with our two-year-old daughter, Gabriella, to visit her parents and grandparents for Norouz (Iranian new year).

Torn apart: Richard has been fighting for Nazanin’s release for more than 70 days

‘If these are indeed the allegations, this is of course farcical – the idea that there is some malevolent network headed by Nazanin and her two year old daughter is nonsense. It is a struggle enough for me to take Gabriella shopping.

‘This is the fantasy of a provincial security agency down in Kerman wishing to assert its national importance.

Many happy returns: Richard held a party outside the Iranian Embassy in London last week to mark daughter Gabriella’s birthday while she is stuck in Iran

‘It has taken it over 70 days for the Revolutionary Guard to put together something that is simultaneously vast and vague, and that could mean absolutely anything.’

‘It is a tragedy that Iran’s government allows the Revolutionary Guard to treat its citizens in this way.’

On Friday (June 10) last week, Richard was joined by friends, family and his MP Tulip Siddiq, to hold a birthday picnic in Hyde Park outside the Iranian Embassy in London to celebrate Gabriella’s birthday.

For more about this campaign go to change.org/freenazanin or email press.uk@change.org for photos, embeddable video and quotes.