Security forces in Karaj arrested Ahmadi in mid-September, according to Aftab News Agency and the pro-opposition Radio Koocheh. An economics reporter, Ahmadi had worked for the semi-official Iranian Students News Agency, or ISNA, since 2006.
Ahmadi contacted his family by telephone after his arrest, but said he did not know the basis for his arrest, the Human Rights House of Iran reported. No formal charges were immediately disclosed.
The state-supported ISNA is run largely by Iranian university students. Originally established to publish news from Iranian universities, it now covers a variety of national and international topics. Four other ISNA journalists were jailed in October 2011.