France on Tuesday accused Iran of employing a policy of state hostage-taking and blackmail, as it called for the release of a French couple held in jail for the last two years.
Activists have long accused Iran of having a deliberate hostage-taking strategy aimed at extracting concessions from the West, but it is rare for a Western government to make such a strong statement.
Teacher Cecile Kohler and her partner Jacques Paris were detained in Iran in May 2022. They are accused of seeking to stir up labour protests, accusations their families vehemently deny.
"France condemns this policy of state hostage-taking and this constant blackmail by the Iranian authorities," the French foreign ministry said in a statement.
Aside from Kohler and Paris, two other French citizens are held by Iran: a man identified only by his first name, Olivier, and Louis Arnaud, a banking consultant who was travelling in Iran and was last year sentenced to five years in jail on national security charges.
"France reiterates its demand for their immediate and unconditional release," the statement said.
It added: "We are also thinking of all the other European hostages in prison in Iran, who are innocent of the absurd charges brought against them in show trials."
Kohler and Paris were also subjected to what France condemned as forced confessions broadcast on Iranian TV after their arrest.
Several foreign prisoners have been released in recent months, including five Americans freed in a complex exchange for billions of dollars in Iranian funds that had been frozen in a South Korean account. No more Americans are believed to be held in Iran.
But the French citizens are among at least a dozen European passport holders, including dual nationals, held by Tehran.
Two of them -- German Jamshid Sharmahd and Swede Ahmadreza Djalali -- risk execution after being sentenced to death on charges their families say are utterly false.
Also held is Swedish EU diplomat Johan Floderus whom prosecutors want sentenced to death on spying charges his family strongly rejects.
Activists say Swedish nationals have been especially targeted over the life sentence given in Sweden to former Iranian prison official Hamid Noury for his role in mass executions in Iran in 1988.