The Iranian regime has appointed one of its most feared prosecutors to interrogate reformists arrested during demonstrations, prompting fears of a brutal crackdown against dissent.

The interrogation of prisoners is now being headed by Saaed Mortazavi, a figure known in Iran as “the butcher of the press”. He gained notoriety for his role in the death of a Canadian-Iranian photographer who was tortured, beaten and raped during her detention in 2003.