Iran and France indicated on Monday that talks on the release of two French citizens held in Iran in exchange for an Iranian national detained by France were progressing.

Iran has been holding Cecile Kohler and her partner Jacques Paris since 2022. An 18-year-old French-German cyclist, Lennart Monterlos, is also being held in Iran after his arrest in June.

France has repeatedly accused Iran of holding Kohler and Paris arbitrarily, keeping them in conditions akin to torture in Tehran's Evin prison and not allowing proper consular protection. The Islamic Republic denies the accusations.

Iranian Foreign Minister Abbas Araqchi suggested in mid-September the French nationals could be exchanged for Mahdieh Esfandiari, an Iranian student living in the French city of Lyon who was arrested this year over anti-Israel social media posts.

"The decision regarding the release of these two individuals and Mrs Esfandiari is currently being reviewed by the competent authorities," Iranian Foreign Ministry spokesperson Esmaeil Baghaei told a news conference on Monday.

"We hope that once the necessary procedures are completed, this will happen soon."

Outgoing French Foreign Minister Jean-Noel Barrot told France Inter radio on Monday: "We have solid prospects of being able to bring them back in the coming weeks."

He added: "we remain fully mobilised and demand their immediate and unconditional release."

According to the semi-official Iranian news agency Tasnim, Iran acquitted French-German national Lennart Monterlos of espionage charges, the chief justice of the southern province of Hormozgan said on Monday.

France in September dropped its case before the International Court of Justice against Iran for violating the right to consular protection of its citizens, a move that signalled there had been progress in efforts to reach a deal.

The case at the ICJ or World Court was widely seen as a bid to pressure Iran over the detention of its citizens. Iran has accused the pair of spying for Israel's Mossad intelligence service.