Seventy university professors were detained after meeting with Iranian opposition leader Mir Hossein Mousavi, according to a website affiliated with the politician.
The Kalemeh website said the professors were taken into custody after a meeting with Mr Mousavi late last night.
The report said it was not clear where the detainees were taken.
The reported detentions are another sign of the expanding crackdown by Iranian authorities on protesters challenging the results of the June 12 presidential elections.
Mr Mousavi has led the challenges, saying he is the rightful winner, not President Mahmoud Ahmadinejad.