Fattahian had been originally sentenced to 10 years in prison for ties to an armed Iranian opposition group. But an appeal court recently overturned his prison sentence and instead condemned him to death.
He was hanged today at Sanandaj prison, despite calls by human rights defenders to halt his execution.
Ahead of the execution, the International Campaign for Human Rights in Iran had described Fattahian as a prisoner of conscience who had been "unjustly charged, sentenced in violation of Iranian law, and been convicted without due process and in the absence of evidence to prove the case against him."
Amnesty International had called on the head of Iran’s judiciary to reduce Fattahian’s sentence on the grounds that he was not tried fairly.
In recent days Iranians had launched a campaign in support of Fattahian on Facebook; some had changed their profile pictures to one of Fattahian.
(by Golnaz Esfandiari)