The arrests came on October 8 after violence erupted
between supporters and law enforcement forces outside Ayatollah Hossein Kazemeyni Boroujerdi's house in the capital, Tehran.
The whereabouts of Boroujerdi and the other detainees remain unclear.
Boroujerdi has been accused by officials of speaking out on matters for which he is not qualified religiously and of sacrilege, according to "The New York Times."
He had ignored a summons for more than a month by the country's Special Court for the Clergy, the newspaper reported.
Speaking to RFE/RL in early October, Boroujerdi accused authorities
of arresting more than 100 of his supporters and of persecuting him since a June 30 religious meeting that he claimed attracted thousands.
Hundreds of Boroujerdi's supporters had clashed with police on October 7 in a bid to prevent his arrest.
Boroujerdi advocates the separation of religion and politics in Iran, whose 1979 Islamic revolution ousted the shah and replaced it with theocratic rule.
In an interview with RFE/RL last week, Boroujerdi complained of increasing government pressure on himself and his followers.
He said he had appealed to the European Union and Pope Benedict XVI to complain of harassment and to note the "suspicious" death of his father in 2002 and subsequent seizure of the mosque at which his father preached. Reuters reported that he similarly contacted UN Secretary-General Kofi Annan to exhort him "to make efforts to spread traditional religion," a call that Boroujerdi has used to criticize religious authorities in positions of political power.
Boroujerdi claimed to RFE/RL that authorities had threatened him with execution.