A United Nations' senior human rights official has said US-led occupation forces had committed "serious violations" of international humanitarian law in Iraq and had ill-treated ordinary Iraqis.
Acting High Commissioner for Human Rights Bertrand Ramcharan said coalition troops were able to act with impunity and urged appointment of an independent figure to monitor their behaviour.
In a report for the world body's Human Rights Commission, Ramcharan also indicated that US male and female soldiers accused of gross abuses of detainees at Baghdad's Abu Ghraib prison could be guilty of war crimes.
"The serious violations of human rights and humanitarian law that have taken place (since US and British troops invaded Iraq in March last year and ousted then president Saddam Hussein) must not be allowed to recur," the report declared.
"It is crucial that protection arrangements be strengthened as a matter of the utmost urgency," it said. An International Ombudsman or Commissioner to monitor respect for human rights in Iraq should be appointed "immediately".
It was, the report said, "a stark reality that there was no international oversight and accountability in respect of the situation that obtained in Iraq" since the invasion.
But the report, which asserted that "everyone accepts" that the US and its allies intended their troops in Iraq to behave well, was criticised by Reed Brody, special counsel to the US-based Human Rights Watch organisation.
The 45-page report cited one former Abu Ghraib detainee, Saddam Abood Al-Rawi, 29, as telling UN investigators he was subjected to 18 days of torture at the US-run prison.
This included the pulling of teeth, kicking and beating and threats of rape, and warnings that he would be killed if he told a visiting international Red Cross team about his treatment.
In a Saddam jail where he had been a political prisoner, the report quoted him as saying, he suffered physical torture but under the occupation forces he was additionally subjected to "humiliation and mental cruelty".
Ramcharan, a British-trained barrister from Guyana and long-time UN official, suggested that among the more serious violations was the jailing of large numbers of Iraqis "without anyone knowing how many, for what reasons, for how long...and how they were being treated".
His report, submitted to US and British officials for comment on Wednesday, cited Iraqis interviewed in Amman as speaking of "arbitrary arrests and detention as an ongoing phenomenon" since the invasion.
In a clear reference to the Abu Ghraib incidents, since when several US soldiers working there have been detained, Ramcharan said "willful killing, torture or inhuman treatment" of detainees was a grave breach of international law.
Such acts "might be designated as war crimes by a competent tribunal," he added.
Ramcharan's spokesman, Jose Luis Diaz, denied there had been any outside effort to have the report watered down. "There was no pressure on this office," he said.