The 47-year-old journalist had been living in exile in France but was detained after reportedly traveling to Iraq and returned to Tehran last year.
According to local media, Zam was hanged on Saturday after the supreme court upheld the death sentence against him.
Zam had been accused of fanning unrest and inciting the 2017 protests. At the time he was running a Telegram channel called Amad News, which had 1.5 million followers.
He fled Iran in 2009 and was given asylum in France. In June, a court sentenced Zam to death, saying he had been convicted of “corruption on Earth”and Iran’s supreme court on Tuesday upheld the verdict.
In addition to being accused of having fanned the protests, Zam was also accused of being party to the destruction of property, interfering in the country’s economic system, working with the United States government, spying for French intelligence, and “spying for the intelligence service of a country in the region”.
“This individual committed criminal and corrupt acts against the security and livelihoods of the Iranian people through running the antagonist Amad News Telegram channel and espionage communication with elements linked with foreign services that are against the Iranian people’s security,” wrote Mizan, the official news website of the judiciary, at the time.
According to Mizan, during his trials Zam confessed to leading the 2017 unrests which led to “a number of our compatriots losing their lives due to the terrorist acts of mercenary elements linked with foreigners” and he confessed to being one of the founders of a council of 29 “regime change” media outlets.