The Observer on Sunday said the rules allowed prison guards to employ such techniques as use of dogs, sleep deprivation and stress positions in breach of the Geneva Conventions.

Citing a letter from the Armed Forces Minister, Adam Ingram, the weekly said a senior British army lawyer assigned to the US-led coalition's legal department in Baghdad contributed to "comments provided by his superiors" when drafting the text.

"It is not known whether the officer supported or opposed the document, but the revelation raises serious questions about who in the army's chain of command knew of the interrogation techniques at Abu Ghraib and when," the Observer noted.

Abuse scandal

Abu Ghraib was at the centre of the Iraq prisoner abuse scandal and the British government had earlier claimed none of its officials had seen or been involved with the document that permitted harsher interrogation techniques.

The document, entitled Interrogation and Counter-Resistance Policy was drawn up by the coalition's Combined Joint Task Force 7, which was tasked with supervising the interrogations of Iraqi detainees.

Another British newspaper, The Independent, reported a senior British officer knew about serious claims of abuse at Abu Ghraib five months before British ministers learned about what was going on.

The officer, described as one of the most senior British military lawyers in Iraq, played a key role in investigating a Red Cross report which revealed that prisoners were stripped naked and locked in pitch-black cells for days, paraded in the nude and verbally abused.