Two French nationals have been handed lengthy prison sentences by a court in Iran after being convicted of espionage, Iranian state media reports.

The reports do not name the defendants but they are believed to be Cecile Kohler, 40, and her partner Jacques Paris, 72, the only French nationals being held in Iran. They were arrested in May 2022 during a tourist trip.

The pair have been found guilty of spying on behalf of both France and Israel, according to the reports.

This announcement comes more than a month after Iranian Foreign Minister Abbas Araghchi indicated that discussions for a prisoner exchange involving French detainees were progressing.

Iran previously suggested Kohler and Paris might be released as part of a deal to exchange them for an Iranian woman detained in France.

Earlier this year, another French tourist, Olivier Grondeau, was released by Iran after serving a five-year sentence for 'conspiracy against the Islamic republic.'

Iran's the judicial news agency Mizan reported that one of the defendants received sentences of six years for spying for France, five years for conspiracy against national security, and 20 years of exile for collaborating with Israel's intelligence agencies.

The other was sentenced to ten years for similar charges, all of which will run concurrently under Iranian law. The exact terms of 'exile' remain unclear, as previous instances of such punishment have seen convicts relocated to isolated regions.

Mizan affirmed that their pre-trial detention would factor into their total sentences and indicated that the verdict could be contested within 20 days.

The French government has accused Iran of arbitrarily detaining Kohler and Paris under conditions likened to torture, claims which Iran has denied.

Human rights organizations have pointed out that foreigners and dual nationals are often arrested for leverage in diplomatic negotiations, only released when Iran expects a quid pro quo.

Kohler and Paris have been discussed as possible bargaining chips for Mahdieh Esfandiari, who has been held in France on terrorism charges, with Iran alleging her detention is also arbitrary.

Currently, Iran is believed to hold around 20 Europeans, including British nationals Craig and Lindsay Foreman, who are facing espionage charges.

Last week, 18-year-old French-German cyclist Lennart Monterlos was acquitted of espionage and released after facing similar charges.