Dominic Raab, Foreign Secretary, last night dampened hopes of an imminent release for Nazanin Zaghari-Ratcliffe, saying reports that Britain was to pay a £400 million debt to Iran for her return were “not accurate”.
Iranian media reports over that weekend claimed that a deal had been reached to free the charity worker after the UK settled a 1970s-era arms debt.
"It's incumbent on Iran unconditionally to release those who are held arbitrarily and, in our view, unlawfully, and the reports, I'm afraid, are not yet accurate in terms of the suggestion of her imminent release," Mr Raab said during a joint press conference with visiting US Secretary of State Antony Blinken.
“We are working very intensively to secure their release,” he said of Mrs Zaghari-Ratcliffe and the small number of other British-Iranian nationals being held by Tehran.
Mr Blink, who is in London for the first time since being appointed by President Joe Biden, spoke to Mr Raab about the threat posed by Islamic Republic at the start of the G7’s first in-person talks in two years.
It came after James Cleverly, Foriegn Office minister, suggested the reports on a deal to free British and American prisoners – including Mrs Zaghari-Ratcliffe – may have been deliberate misinformation by Tehran.
"We have also seen a number of occasions where the Iranian regime have used disinformation, we're hearing inaccurate reports coming out over the last couple of days,” he told Sky News.
"On the one hand, they are saying that these proceedings are legitimate, we don't agree with that at all, but then also saying that they are linked to this legal dispute – it can't be both,” Mr Cleverly said, referring to the criminal charges against Mrs Zaghari-Ratcliffe and the money the UK owes Iran.
"We're making it very, very clear. It is in the hands of the Tehran regime to release these people and they should be released,” he said.
Asked about the debt on Sunday, Mr Raab said: "It's not solely about that.”
"Nazanin is held unlawfully in my view as a matter of international law, I think she's being treated in the most abusive, tortuous way," Mr Raab told the BBC of the conditions of her detention.
Mrs Zaghari-Ratcliffe, 42, of north London, was detained in Tehran in 2016 while taking daughter Gabriella to see her family, as authorities made widely refuted allegations of spying.
She completed a five-year sentence in March, but she and her family were delivered a fresh blow last week when she was given an additional one-year jail term.
Several Arabic and Farsi-language news sites reported over the weekend that Iran was discussing a potential prisoner swap with the US and UK.
On Monday, it was reported by The Guardian that two American-Iranian dual nationals detained in Tehran have been moved to a new location inside Evin prison in a procedure that has previously led to the release of detainees.
Morad Tahbaz and Siamak Namazi, were moved to new cells. Mr Tahbaz was moved on Saturday and Mr Namazi on Sunday to a different block that had previously been used to brief prisoners before being released.
Mr Blinken reiterated that the US has "no closer ally, no closer partner" than the UK, as he hailed the "special relationship" during Monday's press briefing at Downing Street.
He said Mr Biden's victory marked the start of a new chapter in their ties following a turbulent and chaotic period under Donald Trump.
He said it is the 75th anniversary of Sir Winston Churchill describing the "special relationship" between the US and UK, adding: "Three quarters of a century later, that special relationship is enduring. It's effective, it's dynamic, and it is close to the hearts of the American people.
"The work we do together serves our people's interests across a vast array of issues."