Iranian journalist Sasan Aghaei has reportedly been arrested.
The charges against Aghaei, who works for the reformist daily Etemad, are not clear.
The opposition site Kalameh reports that Aghaei was taken away by security forces on the afternoon of August 12 from Etemad's offices of in the Iranian capital.
Later, Aghaei's home was searched and he was transferred to Tehran's Evin prison, the report said.
Aghaei has been arrested several times in the past, including in the 2009 state crackdown that followed the disputed reelection of former President Mahmud Ahmadinejad.
The Paris-based media watchdog Reporters Without Borders says Iran is one of the world's five biggest prisons for media workers.
Earlier this month, the group said 10 journalists and 17 citizen journalists were currently detained in Iran.