Nasrin Sotoudeh, a lawyer for Rahmanipour, denied he had played any role in the unrest
"Mohammad Reza Ali Zamani and Arash Rahmanipour whose cases were confirmed by a Tehran appeals court were hanged on Thursday morning," the ISNA news agency said.
Iran has hanged two men over widespread protests that followed the country's disputed presidential election in June last year, an Iranian news agency has said.
The pair were convicted of being "Mohareb" or enemies of God, and members of the Kingdom's Assembly, an outlawed pro-monarchist group and the People's Mujahideen, a religious movement.
They were also charged with plotting to topple the Iranian government, ISNA said quoting officials.
The executions were the first carried out for election-related incidents.
'Show trial'
Iranian authorities arrested around 4,000 protesters including journalists and reformist politicians in a massive crackdown in the weeks after the disputed election.
The two were among 11 people sentenced to death on similar charges in the wake of post-election protests.
But Nasrin Sotoudeh, Rahmanipour's lawyer, denied that her client had any role in the post-election disruption.
"He was arrested in Farvardin [the Iranian month covering March-April] before the [presidential] election and charged with co-operation with the [monarchist] Kingdom Assembly," Sotoudeh told AFP.
She also said she was prevented from representing Rahmanipour at his "show trial" in July and that many of the charges were brought against him when he was a minor.
"He confessed because of threats against his family," she said, adding that she was shocked at the news of the executions since she and her client's family had still been waiting for word from the appeals court.
Crackdown
Baqer Moin, an Iranian author and journalist, said the execution was a "political decision", likely intended to "set an example and to frighten some of the people who may shout a slogans that are not of the liking of the authorities".
"We don't really know which group they belong to, one of them is a monarchist and the other one is the Mujahideen group, obviously the Mujahideen group is not very popular but little is known about the monarchist group," he told Al Jazeera.
"Their lawyers have said that these people were arrested much before the elections, I suppose that they have been used as an example specifically as we are approaching the anniversary of the revolution."
He said: "It is an attempt to make sure that the radicals within the opposition movements are not going to take the lead in the anniversary of the revolution."
The June 12 presidential election plunged Iran into its deepest internal crisis since the 1979 Islamic revolution and exposed widening political divisions.
The reformist opposition says the election was rigged to secure the re-election of Mahmoud Ahmadinejad, the president.
Denying fraud, Tehran portrayed the protests as a foreign-backed bid to undermine Iran's Islamic system of government.
Two men were hanged Iran on Thursday, following their conviction for playing a role in the bombing of a Shiraz mosque, which killed thirteen people, last April.

Mohammad-Ali Zamani and Arash Rahmanipour were charged with trying to overthrow the government, said the Iranian Students News Agency (ISNA), quoting a statement released by the Tehran prosecutor's office. They were convicted of being "Mohareb", or "enemies of God". They were also charged as being members of a banned monarchist group, the Kingdom Assembly or the Mujahedin Khalq. Prosecutors also claimed that Zamani had met with American forces in Iraq and discussed returning to Iran to carry out political assassinations.

Some media reports have suggested the men were actually executed over last year's election protests. Rahmanipour's lawyer, Nasrin Sotoudeh, clarified that her client played no role in the June election unrest, pointing out to Agence France-Presse that "he was arrested in March–April before the election and charged with co-operation with the monarchist Kingdom Assembly".  She added that he had confessed because of "threats against his family," adding that many of the charges were filed against him while he was a minor — he is now nineteen.  Sotoudeh described the trial as being a "show trial", and commented that she hadn't been allowed to represent him in court. 

After the June election, which was widely disputed, there were several weeks of demonstrations and protests, which saw 4,000 people arrested by the authorities in a crackdown, among them journalists and reformist politicians. Several million people attended the protests, demanding a re-vote. Opposition groups asserted that the elections were rigged to favour president Mahmoud Ahmadinejad, but the government denied it, saying it was a foreign-backed attempt to discredit the Iranian government system.