IRNA quoted the journalist's attorney, Giti Pourfazel, as saying that a court yesterday charged Serajeddin Mirdamadi of plotting against Iran's ruling clerics and ordered his temporary detention.
Pourfazel said Mirdamadi stood accused of spreading lies against the government earlier this year but was freed on bail.
Iran has repeatedly detained journalists on similar charges following the 2009 re-election of former President Mahmoud Ahmadinejad in a vote reformists and opposition figures consider fraudulent.