Eight Iranian intellectuals have written an open letter to UN Secretary-General Ban Ki-moon asking him to use "all international levers for the release of innocent Iranian political prisoners," especially the eldest one, Ebrahim Yazdi, RFE/RL's Radio Farda reports.
Yazdi, head of the Iran Freedom Movement, was arrested by security forces in October for the third time since Iran's controversial presidential election in June 2009.
Yazdi, who was foreign minister in the first Iranian government after the 1979 Islamic Revolution, was previously detained in December 2009, but later released to have open-heart surgery.
Among the signatories of the letter are Nobel Peace laureate Shirin Ebadi, religious thinker Abdolkarim Soroush, and reformist cleric Hassan Yusefi Eshkevari.
Sent on November 24, the letter says the 80-year-old Yazdi is under severe physical and psychological pressure in Tehran's Evin prison. It adds that his life is in danger.
Mehdi Nourbakhsh, Yazdi's son-in-law who lives in the United States, told RFE/RL on November 24 that the authorities had not allowed Yazdi's physician to visit him or his family to give him medicine.
The authors of the letter wrote that they have addressed the letter to Ban because an "unbridled government" rules in Iran which has no regard for the universal laws of human rights or even its own constitution.