Ali Shakouri-Rad was a member of the dissolved Islamic Participation Front which supported opposition leader Mirhossein Mousavi against President Mahmoud Ahmadinejad in the disputed 2009 presidential election.
The opposition says the vote was rigged in favor of Ahmadinejad, allegations the authorities have repeatedly denied.
Thousands of opposition supporters have been detained since 2009, including scores of senior reformist figures.
Many have been released but more than 80 have been jailed for up to 15 years.
The report said Shakouri-Rad was banned from political activity for 10 years and will not be allowed to live in Tehran for a period of 10 years following his sentence. There were no details on when the verdict was issued.
Judiciary officials were not immediately available to comment.
The news comes days after a parliamentary poll, the first nationwide poll since millions of people took to the streets across Iran to protest against the 2009 election results.
The authorities hailed a near 65 percent turnout as a sign of widespread support for the Islamic Republic. The majority of reformists refused to participate, saying the vote was not “free and fair.”
Separately, the opposition Kaleme website, affiliated with Mir Hossein Mousavi, reported that Abdolfattah Soltani, a prominent human rights lawyer, had been sentenced to 18 years in jail for spreading anti-regime propaganda.
Soltani co-founded the Defenders of Human Rights Center along with the respected Iranian human rights lawyer and Nobel peace laureate, Shirin Ebadi.
The website has reported that Narges Mohammadi, an assistant to Shirin Ebadi, was sentenced to six years in prison by an appeals court.
In a separate development, the head of the Islamic Journalists Organization, Nezamedin Mousavi, urged the government to be more tolerant with the media, responding to the brief arrest of the managing director of the semi-official Mehr News Agency.
“Considering the recent harsh confrontations with some media representatives, I ask the judiciary officials to practice more tolerance,” Mousavi was quoted as saying by the semi-official Fars New Agency.
“I also ask the government, which does not have an appropriate interaction and cooperation with the media, not to create tension.”
In an attempt to put more pressure and exert more control on cyberspace, Iran’s Supreme Leader Ayatollah Ali Khamenei ordered the formation of an Internet oversight center that includes top military and political figures.
The report did not give any further details on a group which includes powerful figures in the establishment such as the president, parliament speaker, intelligence minister and the commander of the Revolutionary Guards.
The news comes as the concerns have been growing over the national Internet system which many Iranians fear will give the authorities total control over what content users are able to access, thereby cutting them off from the outside world.
Iranians have grappled with increased obstacles to using the Internet since opposition supporters used social networking to organize protests after the disputed 2009 vote.
In the past month, many Iranians have experienced disruptions to e-mail and Internet access.
