An international human rights group said Friday it has documented three cases of sexual assault against detainees arrested during Iran's post-election turmoil, including one that was supported by an official report but not investigated further. Human Rights Watch accused Iran's judiciary of covering up the abuses and called on it to immediately open investigations and prosecute those responsible. Claims that detainees were raped by their jailers first emerged in August, deeply embarrassing Iran's clerical leadership in the midst of a crackdown on protesters who accused authorities of rigging Iranian President Mahmoud Ahmadinejad's June 12 re-election. The New York-based Human Rights Watch said one of the cases it documented was supported by a report from the medical examiner's office, which the group said reports to Iran's judiciary. Judicial authorities, however, refused to investigate further and threatened to arrest the detainee's family if they spoke out about the abuse, the group said.