TEHRAN: Iran on Tuesday sentenced to death an opposition figure who had lived in exile in France before his arrest last year, and separately upheld a five-year jail term for a French-Iranian academic.

Although they are both parties to a landmark 2015 nuclear deal, Tehran and Paris have seen their relations deteriorate in the past year.

France was among the countries that passed a resolution last week at the UN's nuclear watchdog calling on Iran to clarify whether it had undertaken undeclared nuclear activities in the early 2000s, a move condemned by the Islamic republic.

The 2015 accord gave Iran sanctions relief in exchange for curbs on its nuclear programme, but the agreement has been on life-support since 2018, when the United States unilaterally withdrew.

Opposition figure Ruhollah Zam - who had reportedly been living in Paris before Iran's Islamic Revolutionary Guard Corps announced his arrest in October - was accused of playing an active role in anti-government protests sparked by economic hardship during the winter of 2017-18.

Authorities said he incited unrest through a channel on the Telegram messaging application called Amadnews.

"The court has considered 13 counts of charges together as instance of 'corruption on earth' and therefore passed the death sentence," said judiciary spokesman Gholamhossein Esmaili. Corruption on earth is one of the most serious offences under Iranian law.

Zam was also sentenced to time served over other charges, Esmaili added, noting that the sentences can be appealed.