Hessam Firuzi had warned about the health of jailed student activist Ahmad Batebi and called for his release from prison.
Batebi was arrested in late July and is believed to be in Tehran's Evin prison.
Authorities detained Firuzi at his home in Tehran on October 3.
Firuzi's wife, Mahtab Bordbar, told Radio Farda that the charges against him are not clear.
"I only saw in the court order that he will be transferred to Section 209 of Evin prison," Bordbar said. "They didn't make anything clear for me, there was no talk of the charges against him."
There has been no comment from Iranian officials.