She is now with her family in the Iranian capital, Tehran, Saeid Dehghan said.

He hoped this temporary release would become final, he told the AFP news agency.

The academic was given a six-year jail term on national security charges in May.

She received a five-year term for conspiring against national security and one year for propaganda.

"We have not yet [given] a date for her return to prison, but we hope that this temporary release will become final," Mr Dehghan told AFP without providing further details.

In recent years, Iran has arrested dozens of foreign and dual nationals on national security charges. Some, including British-Iranian charity worker Nazanin Zaghari-Ratcliffe, are on temporary release because of the coronavirus pandemic.

The Iranian authorities do not recognise dual nationality for Iranian citizens and they have not granted French diplomats consular access rights.

The SciencesPo researcher is a specialist in social anthropology and the political anthropology of post-revolutionary Iran, and has written a number of books, including Revolution under the Veil: Islamic Women of Iran.

At the time of her arrest, she was examining the movement of Shia clerics between Afghanistan, Iran and Iraq, and had spent time in the holy city of Qom.