Frenchman Benjamin Brière, detained in Iran since October 2020, will remain in detention.
An Iranian appeals court upheld his 8-year prison sentence for "espionage" and "propaganda" against the regime.
The Court of Appeal would thus have considered that the 37-year-old man would be an “agent in the service of an enemy State”.
"It's distressing and dramatic, the fate of Benjamin is instrumentalized," said his French lawyer Philippe Valent.
The latter underlines that the decision “comes at a time when nuclear negotiations are resuming”.
"We ask the French, American and British authorities to make the release of the hostages a prerequisite for the resumption of negotiations" on nuclear power, he added.
Sentenced last January, Benjamin Brière has always presented himself as a tourist.
He was arrested in May 2020 for taking “photographs of prohibited areas” with a recreational drone in a natural park.
France recently judged by the voice of its Minister of Foreign Affairs Catherine Colonna "unacceptable" the conviction of Benjamin Brière.
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