Mrs Zaghari-Ratcliffe was arrested in April 2016 for plotting to overthrow the Iranian regime and was convicted last year despite her denials, with her family – from Hampstead, north London – campaigning to have her released permanently.
Her lawyer had been hoping to come to an arrangement with prosecutors to extend her three-day release, but it has now emerged that those efforts have proved futile.
According to Richard Ratcliffe, his wife went to see the deputy prosecutor with her lawyer on Sunday morning and was told she would not need to return to jail immediately.
Better yet, on her way back to where her family has been staying in Damavand, northeast of Tehran, the 40-year-old was told her extension had been approved.
Ten minutes after arriving, however, Mr Ratcliffe said the family received another phone call from the prosecutor’s office and were told she would have to be back in her cell by sunset because the necessary permit had not been signed off.
She went back to the office – this time with Gabriella – and was told she would need to go back to jail for a few days until the key signature was received.
In a heartfelt bid to have the decision reversed, Mrs Zaghari-Ratcliffe reportedly said: “How can you take me away from my baby, when she needs me.
“I haven’t done anything wrong – you just extended my cellmate’s furlough, and she is serving a longer sentence for bigger crimes. You know I didn’t do anything in the first place.
“I have spent two-and-a-half years in prison, and I haven’t committed any crime.”
Despite the plea, the prosecutor’s office has stood firm on its stance and Mr Ratcliffe – who has been refused a visa to visit his wife and daughter – has confirmed that his wife is now back in her jail cell.
He said the prospect of her being “picked up in the middle of the night” would prove “even more traumatising” for their young daughter.
“I still find it an extraordinary decision,” he added.
“I did not believe after all the effort it took to get out, it would only be for three days.”
The British Embassy has been informed of the development, which comes just days after Foreign Secretary Jeremy Hunt joined calls for Mrs Zaghari-Ratcliffe to be released permanently.
He said it was important not to forget that she “shouldn’t be in prison in the first place” and promised to continue to push for her permanent release.
The Free Nazanin campaign had said her temporary release came after “positive meetings” with Mr Hunt this month, who is considering providing her with diplomatic protection.
Responding to the news she had returned to jail, her local MP Tulip Sadiq tweeted: “Very sad to hear that Nazanin’s extension was not granted, and she has been taken back into prison this evening. I will provide more of an update later.”
Other prisoners released from the same prison for a few days are still out a month later – something the family had hoped would also happen to Mrs Zaghari-Ratcliffe.
A Foreign Office spokesman said: “We remain very concerned about all our dual nationals detained in Iran, and continue to make decisions in line with what we believe will produce the best outcomes in their cases.
“We do not think it is in the best interests of any of our dual national detainees to provide a running commentary on individual cases.”