Iran sentences French academic Fariba Adelkhah to five years in prison
French Foreign Minister Jean-Yves Le Drian denounced a "political" verdict and demanded Adelkhah's immediate release.
Marchal was released in an apparent prisoner swap in March that drew strong criticism from the United States.
The 61-year-old Adelkhah has remained in custody ever since her arrest. A research director at Sciences Po university in Paris, she is a dual French-Iranian citizen, a status Iran does not recognise.
The academic was "sentenced to five years for gathering and conspiring against national security, and one year for propaganda against the Islamic republic," her lawyer Said Dehghan told journalists. The sentences were to be served concurrently, he said, adding that his client intended to appeal against her conviction.
The punishment caused dismay in France.
"I strongly condemn (this verdict). This sentence is not based on any serious element... it has a political nature," Le Drian said in a statement. Iranian authorities must "immediately free" Adelkhah and grant her a visit by French consular officials, he added.
Her trial opened on 3 March with the final hearing held on 19 April at branch 15 of Tehran's Revolutionary Court.
Adelkhah has been severely weakened by a 49-day hunger strike she mounted between late December and February, her lawyer said.
Argument for appeal
Her French colleague Marchal, who was detained while visiting her in Tehran, is also a researcher at the Centre for International Research (CERI) at Sciences Po. He is a specialist in sub-Saharan Africa, while she is a specialist in Shia Islam.
Marchal was freed after France released Iranian engineer Jallal Rohollahnejad, who faced extradition to the United States over accusations he violated U.S. sanctions against Iran.
Washington has said that it "deeply regrets" that decision.
Dehghan said Marchal's release gives grounds for appeal against the charge of "gathering and conspiring against national security".
"At least two people must be involved for this charge to stand," he said.
Adelkhah's defence team also plans to argue that her personal academic opinion regarding the Islamic dress code enforced in Iran cannot amount to "propaganda against a political system."
Following Adelkhah's hunger strike, her support committee expressed concern over her vulnerability to any outbreak of the coronavirus in the prison where she has been held.
Iran is battling the Middle East's deadliest COVID-19 epidemic, which has claimed more than 6,900 lives.
Dehghan had recently indicated that Adelkhah continued to "suffer from kidney disease as a consequence of her hunger strike."
Arrests of foreign citizens have increased since the United States unilaterally withdrew from a landmark nuclear deal between Iran and major powers in 2018 and reimposed crippling sanctions.
Those detained, who have included a number of dual nationals, have mostly been accused of spying or of acting against Iran's national security.
Iran's female political prisoners
Iran is holding numerous women in jail on political charges. They include human rights activists, journalists, artists and simply engaged citizens. By Shabnam von Hein
Bahareh Hedayat: A women's rights activist and prominent figure in the student movement in Iran. In 2010, shortly before her wedding, she was arrested and ultimately sentenced to 10 years in prison. She was head of an organisation fighting for political reforms and against human rights violations
Nazanin Zaghari-Ratcliffe: An employee of the Thomson Reuters Foundation, she has been in jail since April, 2016. She has both British and Iranian citizenship, and wanted to visit family in Iran with her two-year-old daughter. She is accused of participating in efforts "to cause the soft toppling of the Islamic Republic." Her foundation, which educates journalists worldwide, has called the allegations groundless
Zahra Rahnavard: Wife of opposition politician Mir Hossein Mousavi, she is perhaps the most well-known of Iran's female political prisoners. After the disputed presidential elections in 2009, she backed her husband. The sculptor and academic has been under house arrest with her husband since February 2011 without charges
Narges Mohammadi: A human rights activist, she was sentenced to 16 years in prison in May 2016, although her work is seen as peaceful. At the end of June, she began a hunger strike after authorities restricted telephone contact with her young son and daughter. After 20 days on hunger strike, she was granted permission to speak once a week with her children
Homa Hoodfar: The Canadan-Irish-Iranian anthropologist has been jailed at Tehran's Evin Prison since 6 June 2016. The renowned academic was arrested during a private visit to Iran. She had planned to research women in Iranian politics. She was accused of creating security problems in the Islamic Republic by taking part in feminist activities
Reyhaneh Tabatabaei: The political journalist has been arrested many times, most recently in January 2016. Reyhaneh Tabatabaei was accused of "propaganda against the state." She supported reform activists. Tabatabaei was sentenced to a year in prison and was handed a two-year employment ban. The Revolutionary Court also prohibited her from participating in any political activities for two years
Fariba Kamalabadi: After eight years behind bars, Fariba Kamalabadi (third from right) was granted temporary release in May. Until 2008, she was one of Iran's leading Baha'i figures. She was sentenced to 20 years for her religious beliefs. While on release she visited Faezeh Hashemi, daughter of former president Ali Akbar Rafsanjani. Several grand ayatollahs denounced the visit as a "betrayal of Islam"
A support committee, which was set up to campaign for their release, condemned Adelkhah's conviction and jail sentence as "Kafkaesque".
"It was not a proper legal process. There was clearly no open debate," said committee member Jean-Francois Bayart, a Geneva based academic.
The support committee also called on scientific institutions to "suspend all scientific co-operation with Iran".
Bayart said Adelkhah had been caught up in wider political issues over which she had no control.
Iran has been increasingly critical of European governments, particularly France, over their failure to do more to save the 2015 nuclear deal by enabling companies to get round renewed U.S. sanctions.
"The intensity of this arm-wrestling contest does not surprise us," Bayart said. "It's an opaque and arbitrary process and an utterly asymmetric bargaining situation because one of the protagonists is in jail."
But Bayart added that despite the after-effects of her hunger strike, Adelkhah remained "extremely combative, lucid and determined".
Marchal is not the only Western national to have been freed by Iran in a prisoner swap in recent months. In February, Iran released an unidentified German in exchange for Iranian Ahmad Khalili, who was in custody for circumventing U.S. sanctions.
In December, it freed U.S. academic Xiyue Wang in exchange for scientist Massoud Soleimani and said it was open to further swaps. (AFP)