Nazanin Zaghari-Ratcliffe, the British woman held in an Iranian prison for more than 18 months, is eligible for early release, according to reports.
The news came via Mrs Zaghari-Ratcliffe Iranian lawyer, who saw the change in the prisoner's status on an Iranian judiciary database.
Richard Ratcliffe, Nazanin's husband, has said he is "cautious" about the news, but that he hoped his wife would be home soon.
Speaking to ITV News, Mr Ratcliffe said: "It's definitely positive, but ... these things can take different directions. On the computer it says it's positive, it's definitely moved forwards, but it still needs someone to unlock the door and released her."
He said he hoped his wife could be home for Christmas. "I hope, I really hope. It's a lot closer today that it was yesterday," he said.
- Richard Ratcliffe speaks to ITV News:
Tulip Siddiq, Mrs Zaghari-Ratcliffe's local MP, confirmed she had spoken to Mr Ratcliffe about the matter.
"This news is a glimmer of light at the end of a dark tunnel for my constituents Richard, Nazanin and [their daughter] Gabriella," Ms Siddiq said.
"It has given Nazanin a real boost of positive energy, and now we wait impatiently to see what happens next.
"Although we do not want to celebrate prematurely, it would be the perfect Christmas gift to see Nazanin released and back with her family where she belongs.”
According to Mrs Zaghari-Ratcliffe's sister-in-law, Rebecca Jones, Mrs Zaghari-Ratcliffe's lawyer discovered that on a judiciary database the case had been marked eligible for early release.
"That's a change, we thought it was always a closed case," Ms Jones said.
"It doesn't mean to say she is going to get early release, but it's definitely a positive step ... The lawyer is much more positive and Nazanin is much more positive."
Mrs Zaghari-Ratcliffe, who holds dual UK-Iranian nationality, is serving a five-year sentence over allegations, which she strongly denies, of plotting to overthrow the Iranian government.
She was arrested in Tehran airport in 2016 during a trip to the country to show her baby daughter Gabriella to her parents.
Her case achieved new prominence after Boris Johnson appeared to tell a parliamentary committee that Mrs Zaghari-Ratcliffe was in Iran training journalists - something the Iranian authorities have accused her of, but which she denies.
The foreign secretary later acknowledged he had misspoken.
During a subsequent trip to Iran, Mr Johnson's held a "forthright" meeting with Iran's president Hassan Rouhani about Mrs Zaghari-Ratcliffe's case, according to a spokesman.