Iran on Saturday executed Ruhollah Zam, a former opposition figure who had lived in exile in France and was implicated in anti-government protests, days after his sentence was upheld.

State television said the "counter-revolutionary" Zam was hanged in the morning after the supreme court upheld his sentence due to "the severity of the crimes" committed against the Islamic republic.

Judiciary spokesman Gholamhossein Esmaili had on Tuesday said Zam's sentence was upheld by the supreme court "more than a month ago".

London-based rights group Amnesty International, in a statement after his verdict was confirmed, described Zam as a "journalist and dissident".

It said the confirmation marked "a shocking escalation in the use of the death penalty as a weapon of repression."

Iran's Revolutionary Guards announced the arrest of Zam in October 2019, claiming he had been "directed by France's intelligence service".

State television said he was "under the protection of several countries' intelligence services."

The official IRNA news agency said he was also convicted of espionage for France and an unnamed country in the region, cooperating with the "hostile government of America", acting against "the country's security", insulting the "sanctity of Islam" and instigating violence during the 2017 protests.

At least 25 people were killed during the unrest in December 2017 and January 2018 that was sparked by economic hardship.

Zam, who was granted political asylum in France and reportedly lived in Paris, ran a channel on the Telegram messaging app called Amadnews.

Telegram shut down the channel after Iran demanded it remove the account for inciting an "armed uprising".

'Corruption on earth'

Zam was charged with "corruption on earth" -- one of the most serious offences under Iranian law -- and sentenced to death in June.

State television aired an "interview" with him in July, in which he appears as saying he believed in reformism until he was detained in 2009 during protests against the disputed re-election of ultra-conservative president Mahmoud Ahmadinejad.

He also denied having instigated violence through his Telegram channel.

Amnesty has repeatedly called on Iran to stop broadcasting videos of "confessions" by suspects, saying they "violate the defendants' rights".

Zam is one of several people to have been put on death row over participation or links to protests that rocked Iran between 2017 and 2019.

Navid Afkari, a 27-year-old wrestler, was executed at a prison in the southern city of Shiraz in September.

The judiciary said he had been found guilty of "voluntary homicide" for stabbing to death a government employee in August 2018.

Shiraz and several other urban centres across Iran had been the scene of anti-government protests and demonstrations at the time over economic and social hardship.

Three young men were also sentenced to death over links to deadly 2019 protests, but Iran's supreme court said last week that it would retry them over a request by their defence team.

Their sentences were initially upheld by a tribunal over evidence the judiciary said was found on their phones of them setting alight banks, buses and public buildings during the wave of anti-government protests.

Amnesty International said Iran executed at least 251 people last year, the world's second highest toll after China.