Reiss was arrested at Tehran airport on 1 July 2009 on her way home to France via Beirut. Iranian authorities alleged that Reiss took photographs of the 2009 Iranian election protests in Isfahan and emailed them to a friend, an act which constituted potential espionage against the Islamic Republic in the eyes of Iranian prosecutors. News of her arrest did not become public for several days, during which time the French government tried unsuccessfully to obtain her release.

 

When it became clear that Iran intended to put Reiss on trial, officials at the highest level of the French government publicly mobilized on her behalf; French Foreign Minister Bernard Kouchner called the charges against her "absurd" and President Nicolas Sarkozy dismissed them as "pure fantasy".    She was visited by the ambassador of France in Tehran, Bernard Poletti, on 9 July 2009.  

 

Her trial began in Tehran on August 8, 2009   , at the same time as Nazak Afshar, a French-Iranian employee of the French Embassy and Hossein Rassam, an Iranian employee of the British embassy. The Swedish Presidency of the European Union expressed concern over the trial and demanded that the prisoners be released promptly, saying, "The Presidency reiterates that actions against one EU country - citizen or embassy staff - is considered an action against all of EU, and will be treated accordingly."    She has been released on bail and was residing at the French embassy, unable to leave the country pending the final outcome of her trial.

 

President Mahmoud Ahmadinejad of Iran issued a statement signaling his government's willingness to release Reiss, but clarifying that her release depended on the "approach and behavior adopted by French officials.    He declined to elaborate further as to what he expected from the French government, saying only that "they know what to do." France has suggested that Iran is attempting to blackmail Paris into releasing an Iranian agent jailed in France for the 1991 murder of an exiled former prime minister in exchange for Reiss's freedom, a swap that they have vigorously opposed.  

 

Clotilde Reiss was freed on Sunday the 16.5.2010. She arrived in Paris on Sunday the 16 May 2010 about 13:00 H and was receveied at the Elysee by president Nicolas Sarkozy. In a statement, she thanked her supporters and the president, "who proclaimed my innocence as soon as I was arrested".