An ally of Iranian opposition leader Mirhossein Mousavi has been detained, a reformist website said, in a move that could signal increased pressure by the authorities on pro-reform foes of President Mahmoud Ahmadinejad, Reuters reported.
Mowjcamp.com said Alireza Hosseini Beheshti, who heads an opposition committee looking into alleged abuse of detained protesters after the disputed June election, was detained on Tuesday on the orders of Tehran's prosecutor.
Officials were not immediately available for comment.
Beheshti's office has issued estimates of the number of people killed in post-election unrest that are much higher than the official death toll of around 26 people. The opposition says more than 70 people died during the street protests.
Also on Tuesday, judiciary officials closed down the office of pro-reform cleric Mehdi Karoubi and seized documents and discs, the ILNA news agency reported earlier.
Mousavi and Karoubi, who finished second and fourth respectively in the election, say the presidential poll was rigged to secure Ahmadinejad's re-election. The authorities deny the charge.