The British-Iranian mother was allowed out of her cell this week and was able to spend time with young Gabriella, having been held since her arrest in April 2016 for plotting to overthrow the Iranian regime.
She has always denied the allegation but was convicted last year, and her family have since been 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 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.