Iran state TV says Tehran has released detained British-Australian academic Kylie Moore Gilbert in exchange for three Iranians held overseas.
In letters that were smuggled out of Evin prison earlier this year, Ms Moore-Gilbert said she had turned down an offer to spy for the Iranian government in return for a reduced sentence.
According to Iranian state media, she was exchanged for an Iranian businessman and two Iranian citizens "who had been detained abroad".
You can receive Breaking News on a smartphone or tablet via the BBC News App. She is one of several Westerners held in Iran on internationally criticised espionage charges that their families and rights groups say are unfounded. Dr Kylie Moore-Gilbert, from the University of Melbourne, has reportedly been sentenced to 10 years behind bars in Tehran, Iran.
It was not immediately clear when Moore-Gilbert would arrive back in Australia.
The timing of her release also remained unclear, but the TV footage showed faint sunlight streaming through windows during the swap.
Moore-Gilbert has gone on hunger strikes and pleaded for the Australian government to do more to free her.
Her release comes exactly one month after she was reported to have been moved from the desert prison of Qarchak, one of the most risky women's prisons in the country, to an unknown location.
Over the summer, she was transferred to the remote Qarchak Prison, east of Tehran, as fears escalated over the spread of the coronavirus in the country's notoriously crowded prisons.