Yadali reportedly has been charged with spreading lies in connection with two of his books that were published several years ago with the approval of Iran's Culture Ministry.
The date of Yadali's trial has not been announced. His release comes a few days after his wife and an Iran-based human rights group expressed concern about his fate.
(with material from agency reports)
RFE/RL Iran Report
SUBSCRIBE For regular news and analysis on Iran by e-mail, subscribe to "RFE/RL Iran Report."