From Human Rights Watch:

A notoriously abusive Iranian prosecutor, Saeed Mortazavi, has been put in charge of the investigation of detained reformist leaders and party officials amidst a widening security crackdown in Iran following the disputed June 12 election, Human Rights Watch said today. The role of Mortazavi, who has been implicated in past cases of torture, illegal detention, and coercion of false confessions, came to light as Iran’s powerful security forces sought to quell post-election protests that have now continued for over a week.
“Iran is in the midst of a violent and arbitrary crackdown on reformist protesters that has already claimed lives and has led to over a thousand arrests,” said Sarah Leah Whitson, Middle East and North Africa director at Human Rights Watch. “The role of Mortazavi in the crackdown suggests that the authorities are preparing to bring trumped-up charges against its opponents.”