New York: Human rights groups urged the U.N. General Assembly to appoint a special envoy to investigate abuses in Iran, alleging detainees held after disputed elections there have been raped and tortured.
Iran has called the allegations baseless.
Human Rights Watch and the International Campaign for Human Rights in Iran on Monday said about 400 prisoners remained in custody for their suspected involvement in election protests following the June 12 vote in which President Mahmoud Ahmadinejad was re-elected.
The opposition says the poll was rigged.
As many as 72 Iranians have been killed by government forces since the election, and several have been tortured and sexually abused, the groups alleged in a news conference near United Nations headquarters.
"Member states of the United Nations should use (Ahmadinejad`s) upcoming visit to the U.N. General Assembly to address Iran`s Human rights crisis," the groups said in a statement.
Ahmadinejad was due to address the U.N. General Assembly on Wednesday, with several groups preparing to protest his presence at U.N. headquarters in New York.
Ebrahim Sharifi, a 24 year-old computer science student from Tehran, said he was among the prisoners questioned, beaten and raped by Iranian interrogators during a harrowing week of detention in late June.
"He tied my hands to a handcuff that was connected to the wall, tied my feet, and pulled down my underwear," Sharifi said of his interrogator, speaking to reporters by phone. "He then sexually assaulted me."
Sharifi spoke from Turkey, where he fled last month after he said Iranian intelligence officials threatened to kill his family.
The alleged sexual abuse of detainees has become an incendiary subject in highly religious Iran. Defeated presidential candidate Mehdi Karoubi is among opposition members who have raised allegations that political detainees are being abused.
Parliamentary Speaker Ali Larijani has received and dismissed at least 100 reports of sexual abuse carried out on political detainees, said Hadi Ghaemi, a coordinator for the International Campaign for Human Rights in Iran.