President Emmanuel Macron says Iran has released a French citizen who was detained on national security charges almost two years ago.

Louis Arnaud, a banking consultant in his 30s, was arrested in September 2022 – accused of participating in anti-government protests and of contributing to anti-government propaganda.

He was sentenced to five years in jail in 2023.

“Louis Arnaud is free. He will be in France tomorrow after a long incarceration in Iran,” Mr Macron posted on X.

The president thanked Oman for helping to secure his freedom and urged Iran to release three other French prisoners.

The three others are teacher Cecile Kohler and her partner Jacques Paris, and a man identified only by his first name, Olivier.

“This evening, I also think of Cecile, Jacques and Olivier. I am calling on Iran to liberate them without delay,” Mr Macron said.

Mr Arnaud’s family stated in the past that he was celebrating the birthday of one of a group of backpackers he had met on his travels when they were stopped by the Islamic Revolutionary Guard. All of the others who were detained, including other foreigners, have since been released.

His arrest took place as protests started to sweep across Iran in 2022, sparked by the death of 22-year-old Mahsa Amini in custody.

Mr Arnaud was held at the notorious Evin prison in the capital, Tehran, which has long been criticised by rights groups.

Human Rights Watch has accused authorities at the prison of using threats of torture and of indefinite imprisonment, as well as lengthy interrogations and denial of medical care for detainees.

The release comes as bilateral relations between Paris and Tehran have deteriorated in recent months.

France has said the detention of its citizens are arbitrary arrests equivalent to state hostage taking. It’s also increasingly concerned by Iran’s activities in the Middle East and the advance of its nuclear programme.