Gholam Hossein Mohseni Ejehi says Mahmoud Doaei was summoned today for a second round of questioning and that the case will go to trial.
Ejehi says a ban on covering "seditionist leaders" ordered by Iran's Supreme National Security Council, the country's highest decision-making body, remains in place.
Moderates say there is no official ban and that the order was unilaterally imposed by hardliners.
Doaei, an editor at Ettela'at, one of Iran's oldest newspapers, has said he doesn't consider Khatami a seditionist. The case against him comes after the paper published the former president's photo last week.