Isa Saharkhiz said in an open letter on July 25 that if the head of Iran's judiciary, Ayatollah Sadeq Larijani, did not take action on his grievance in the coming month he would take his case to international courts and other bodies.
Saharkhiz has been in jail since he was detained in mass arrests following the disputed presidential election in June 2009.
Before his imprisonment, Saharkhiz had written an outspokenly critical letter to Supreme Leader Ayatollah Ali Khamenei.
Despite spending nearly a year in prison, there has been no verdict in Saharkhiz's case.
After a July 18 court session, Saharkhiz lodged his complaint against Khamenei, President Mahmud Ahmadinejad, and chief prosecutor Gholamhossein Mohseni-Ejei.
U.S.-based Mehdi Saharkhiz, Saharkhiz's son, told Radio Farda that his father wanted the open letter to draw attention to the three men's conduct, even if the Iranian judiciary did not investigate the matter.
Mehdi Saharkhiz said that "these three men" were in power during his father's arrest and sentencing. "Though they did not issue the orders [in his father's case], they remained silent, which makes them an equal partner in crime."
He added that the family has had limited contact with Isa Saharkhiz during his imprisonment. "My father is in good health psychologically," Mehdi said. "It is his physical health that has worried us."
Mehdi Saharkhiz said his father's rib was broken during his arrest. He also said his 57-year-old father had been tortured in prison, calling his treatment "inhuman."
Since Isa Saharkhiz's jailing, little has been known about his condition in prison.