The United Nations Children's Fund on March 3 expressed concern about the health of an elderly former staff member who was jailed in Iran last week.
Baquer Namazi was arrested on February 22 and taken to Tehran's Evin Prison, where his son Siamak has been jailed since October. Both Namazis are dual U.S.-Iranian citizens.
Baquer Namazi, now 80, was an Iranian provincial governor who served as UNICEF's representative in various African countries before retiring in 1996.
"Current and former UNICEF colleagues are deeply concerned about the health and well-being of Baquer," UNICEF said in a statement. "We hope he will be reunited soon with his wife and loved ones."
The elderly Namazi has a serious heart condition which requires special medication, his wife said.
Iran has not issued formal charges against either man. Friends of Siamak Namazi have said that he may have become a pawn in factional struggles among hardliners, pragmatists, and reformers.
Elections in Iran last week strengthened centrists and reformists allied with President Hassan Rohani.
With reporting by Reuters