"Today he was summoned to the prosecutor's office... He was arrested and transferred to Evin prison," in northern Tehran, his wife Masoumeh Shahriari told Fars news agency.
Shahriari said the public prosecutor had "lodged a complaint" against Pourazizi, who was trying to negotiate being released on bail.
"We have not been informed about the amount of money needed for the bail," she said.
Iran's press watchdog banned Bahar last week because of an article seen by many as questioning a core belief of Shia Islam.
Culture Minister Ali Janati said the article "foments religious conflicts" and that the daily had received earlier warnings.
And judiciary chief Ayatollah Sadegh Larijani warned Wednesday that his department will "act with determination against those who falsify the history and try to undermine the fundamentals of the regime."
Iran's new president Hassan Rouhani, who has the support of reformists and moderates, pledged to work for more social freedom during his election campaign.
Bahar and several other reformist dailies, notably Shargh, only resumed publication at the end of 2012 after a ban lasting several years.
