Fariba Adelkhah, an Iranian-French academic, has been released, though it is unclear how long she will have to stay in Iran before returning to France, her lawyer said on Saturday.

The French foreign ministry called for Adelkhah’s freedom to be restored, including the right to return to France if she so desired, in a statement announcing her release on Friday.

“She was freed last night and is now at her home,” Hojjat Kermani told Reuters.

“Legally, her file is considered completed, and legally there should be no problem to leave the country, but this issue has to be reviewed. So … it is not clear how long it will take,” said Kermani.

Adelkhah has been in prison since her arrest in 2019 during a visit to Iran. She is one of seven French nationals detained in Iran, a factor that has worsened relations between Paris and Tehran in recent months.

Iranian authorities sentenced Adelkhah in 2020 to five years in prison on national security charges. They moved her to house arrest later but in January she returned to jail.

Adelkhah has denied the charges. France has called them “politically motivated” and repeatedly called for the release of the researcher affiliated with Paris’ prestigious Sciences Po university.

In recent years, Iran’s elite Revolutionary Guards have arrested dozens of dual nationals and foreigners, mostly on charges related to espionage and security.

Rights groups have accused Iran of trying to extract concessions from other countries through such arrests. Iran, which does not recognise dual nationality, denies taking prisoners to gain diplomatic leverage.

Kermani said he spoke to Adelkhah following her release Friday night. “She is well. She was happy just like any prisoner would be when released from jail and her sentence ends,” he said.