Nazanin Zaghari-Ratcliffe is at an airport in Tehran waiting to leave Iran, where she has been detained since 2016.
The British-Iranian mother and fellow detainee Anousheh Ashoori both travelled to the airport this morning, according to their lawyer.
Tulip Siddiq, the local MP for Ms Zaghari-Ratcliffe at her home in the UK, later confirmed the aid worker had arrived at the airport in the Iranian capital and was “on her way home”.
It comes almost six years after Ms Zaghari-Ratcliffe was first detained in the country, and five years since Mr Ashouri’s arrest.
Iran sentenced Ms Zaghari-Ratcliffe – a project manager for the Thomson Reuters Foundation, the charitable arm of the Reuters news agency – to five years in prison in September 2016 after accusing her of “plotting to topple the Iranian regime”, a charge she has always denied.
Her ordeal began after she visited the country in mid-March 2016 to spend time with family members for Nowruz (New Year), only to be detained on her way home at Imam Khomeini Airport on 3 April.
