Alleging that the White House or Pentagon may have been involved in the cover-up, Brigadier-General Janis Karpinski on Tuesday said those with 'full knowledge' of what transpired at Abu Ghraib worked to keep her from discovering the truth.

"A very reliable witness has made a statement indicating that, not only was I not included in any of the meetings discussing interrogation operations, but specific measures were taken to ensure I would not have access to those facilities, that information or any of the details of interrogation at Abu Ghraib or anywhere else," she said.

Involvement

Karpinski – now suspended from her post after pictures of the prisoner abuse came to light - said the cover-up could have involved the White House or Pentagon.

She had earlier said that a military intelligence commander had told her that Iraqi detainees should be "treated like dogs".

Photographs of hooded Iraqi prisoners being abused by occupation forces fuelled Arab and international anger, undermining US efforts to portray itself as the custodian of freedom and human rights.

In the United Kingdom, an Iraqi witness told a court hearing last week that UK soldiers had tortured detainees by beating and kicking them and pouring freezing water over them.

One Iraqi detainee is said to have died under interrogation.