Iran sentences former exiled opposition figure to death
"The court has considered 13 counts of charges together as instances of 'corruption on earth' and therefore passed the death sentence," judiciary spokesman Gholamhossein Esmaili said.
The Islamic Revolutionary Guard Corps announced the arrest of Zam in October last year, describing him as a "counter-revolutionary" who was "directed by France's intelligence service".
Corruption on earth is one of the most serious offences under Iranian law.
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Zam was also sentenced to time served over other charges, Esmaili added, without elaborating.
The sentence could be appealed before the supreme court, he said, quoted by the judiciary's official website.
Zam, who reportedly lived in Paris, ran a channel on the Telegram messaging application called Amadnews.
At the time, he was accused by authorities of playing an active role in anti-government protests sparked by economic hardships during the winter of 2017-18.
Telegram shut down Amadnews after Iran demanded it remove the account for inciting an "armed uprising".
According to Zam's indictment published in February, he was accused of having "committed offences against the country's internal and external security" and "espionage for the French intelligence service", alongside "corruption on earth".
He was also accused of having insulted the "sanctity of Islam".