"Upon witnessing such cases, the ICRC interrupted its visits and requested an explanation from the authorities. The military intelligence officer in charge of the interrogation explained that this practice was 'part of the process'."
It said it met prisoners who were being held naked in complete darkness. Others had been held naked and were allowed to dress, but given only women's underwear.
The Red Cross visit took place two months before pictures were taken of US troops abusing prisoners, which later led to criminal charges against seven soldiers.
Those pictures appeared in the media last month, causing international outrage and prompting apologies by US President George W Bush and other senior officials. Washington said it believed the practices were isolated incidents of aberrant behaviour by individuals and not its usual practice.
The newspaper said the Red Cross report showed the organisation alerted Washington as early as October to maltreatment in Baghdad's Abu Ghraib prison.
But US Defence Secretary Donald Rumsfeld and others have said they were only aware of a problem when the case revealed by humiliating photographs was opened by the military in January.
Rumsfeld, who has faced calls for his resignation from some US newspapers and from opposition Democrats, offered an apology on Friday for the suffering that Iraqi prisoners faced at the hands of the American military.
- REUTERS
Press Release:
Red Cross explains position over detention report and treatment of prisoners
Red Cross Director of Operations Pierre Krahenbuhl
Includes opening statement and points raised in response to questions