According to the reports, Khazali was arrested on October 13 while traveling. The reason for his arrest and his whereabouts are unknown.
Khazali -- who was also arrested in the postelection crackdown and released on bail -- is best-known for his blog, in which he has often criticized President Mahmud Ahmadinejad and poked fun at the clerics.
Last year Khazali, an ophthalmologist, claimed that Ahmadinejad has Jewish roots. In March he wrote that Ahmadinejad had changed his biography on his personal website to pretend that he was among those Iranians who fought in the Iran-Iraq War and defended their country.
Accusing Ahmadinejad of lying, Khazali said he had asked Mohsen Rezai, the commander of the Revolutionary Guard during the war, and the Rezai had confirmed that the Iranian president was not at the front.
In August Khazali helped organize an online debate with opposition leader Mehdi Karrubi about the future of the Green Movement and other issues including the rule of the supreme jurist (velayat faqih), the basis of Iran's political system.
Khazali's father, Ayatollah Abolghassem Khazali, distanced himself from his son in a statement issued after last year's disputed presidential vote, in which he said that his son had "deviated" from the right path for a long time.
-- Golnaz Esfandiari