A U.S. human rights group says medical examinations show that former terrorism suspects once held by the United States had been tortured.

Guantanamo detainees (file photo)

The Massachusetts-based Physicians for Human Rights conducted an evaluation of 11 detainees who were freed without charge after being held at U.S. prisons in Guantanamo Bay, Cuba; Iraq and Afghanistan.

The group says the former detainees detailed beatings, sleep deprivation, electric shock, shacklings, forced nakedness, severe stress positions, humiliation, sexual assault, and being spit and urinated on.

The U.S. government has defended its interrogation techniques and has consistently said it does not torture prisoners.

The report by Physicians for Human Rights said the findings cannot be generalized since so few people were examined.  But it said the patterns of abuse are consistent with numerous governmental and independent investigations of ill-treatment of detainees.

One examiner said the team found clear physical and psychological evidence of torture and abuse, often causing lasting suffering.

In response to a Senate hearing Tuesday about agressive interrogation techniques on terror suspects, Tony Fratto, a White House spokesman, said it has always been the policy of the government to treat detainees humanely.  He said abuse has never been the policy of the government.