The husband of an imprisoned British mother has spoken of her anguish at being returned to her cell after a three-day release.
Nazanin Zaghari-Ratcliffe was sentenced to five years' imprisonment for spying in 2016, but maintains her innocence, saying she was on holiday to introduce her daughter to her family in Iran.
In an open letter to Iran's foreign minister Javad Zarif, Richard Ratcliffe has said his wife was deeply upset at being forced back to prison after the release, which he branded a 'cruel game'.
The news comes as Middle East minister Alistair Burt held talks with Iranian deputy foreign affairs minister Abbas Araghchi in Tehran about the situation.
Foreign Secretary Jeremy Hunt has promised to heighten efforts aimed at securing the British-Iranian's release after she passed out during a panic attack and had to be taken to a prison clinic earlier this week.
British mother Nazanin Zaghari-Ratcliffe was released from prison in Iran for three days earlier this week. Pictured: Mrs Zaghari-Ratcliffe saying goodbye to her daughter Gabriella
Mr Ratcliffe said an Iranian official called his wife's father and warned him to ensure UK diplomats did not contact her while she was out of jail.
The letter from Mr Ratcliffe stated: 'As Nazanin was being released, her interrogator called her father to privately warn him that the British Embassy should not visit her, if she wanted to stay safe.