1046 GMT July 17, 2018
Rehman, a Pakistani by nationality, is a professor of Islamic law and Muslim constitutionalism at Brunel Law School, IRNA reported.
He is replacing Asma Jilani Jahangir who was a Pakistani human rights lawyer and social activist.
Jahangir suffered from a stroke leading to brain hemorrhage in Lahore on 11 February 2018 and later died in hospital.
Due to using invalid sources especially anti-Iran terrorist Mujahedin-e Khalq Organization (MKO), Tehran has not so far recognized many reports as regard human rights conditions in Iran.