|The report says the US asked other countries to interrogate prisoners on its behalf [GALLO/GETTY]
Governments around the world, including those of Arab and European states, have colluded in the secret detention of terrorism suspects, UN investigators have reported.
An extensive report, released on Wednesday, paints a disturbing picture of a systematic secret detention programme involving many countries.
Officials found that secret detention "may even amount to a crime against humanity".
The 222-page document, which will be presented at a forthcoming meeting of the UN Human Rights Council, is the result of several years of investigation, and notes that secret detention is "a manifold human rights violation that cannot be justified under any circumstances".
Despite clear laws that outlaw the secret detention of prisoners in both war and peace, the investigators concluded that in the years following the 9/11 attacks, several countries took part in the US-run secret detention programme.
Criticisms of US detention policy since 2001 are nothing new, but the report will make for uncomfortable reading for leaders in countries accused of colluding with Washington in the CIA's now defunct rendition and detention programme.
The UK, Canada, Australia and Germany are all accused of "taking advantage of the situation of secret detention," by sending questions and receiving information from prisoners held in proxy detention.
The report also notes that the US "asked partners with poor human rights records to secretly detain and interrogate persons on its behalf," accusing Jordon, Egypt, Syria, Morocco, Pakistan, Ethiopia, Djibouti, and possibly Uzbekistan of holding prisoners on behalf of the CIA.
The authors admit that some of the claims of complicity cannot be confirmed, but say the "consistency of many of the detailed allegations provided separately by the detainees adds weight" to arguments placing the countries at the centre of an international extra-legal detention system.
While many of the allegations in the report date back to the Bush years, investigators criticise Barack Obama, the US president, for not going far enough in overhauling the system he inherited on taking office.
While the report acknowledges Obama's achievements, it says there is more to do, including revealing the whereabouts of prisoners who have disappeared in the system.
"Clarification is required as to whether detainees were held in CIA 'black sites' in Iraq and Afghanistan or elsewhere when President Obama took office, and, if so, what happened to the detainees who were held at that time," the report says.
The issue of what has happened to prisoners held in US secret detention in the past extends beyond those who were in US custody when Obama took office.
|Authors want clarification over whereabouts of prisoners held in 'black sites' [EPA]
The report details the case of a prisoner who disappeared before Bush left the White House, Mustafa Setmariam Naser.
The author of a number of books and other publications on Islam and jihad, the Syrian and Spanish national was seized in Pakistan in 2005 and handed over to the US authorities. He has not been heard of since, although last year the FBI said he was no longer in US custody.
A June 2009 statement from the CIA on the issue of Naser's whereabouts said that the agency "could neither confirm nor deny the existence or nonexistence of records responsive to your request," adding that even if the CIA did have the records, they would be classified.
Campaigners now believe that Naser could be in Syrian custody and are calling on the US government to reveal where he is being held.
The report also attacks the Obama administration for its treatment of prisoners in Afghanistan, specifically those held in a prison at Bagram Airbase, describing the situation there as one of "great concern".
The US is holding around 650 prisoners at Bagram. Earlier this month the Obama administration released a list of their names, the first time prisoners held in Afghanistan have been formally identified.
The UN investigators urged the US to release additional information, "on the citizenship, length of detention and place of capture of all detainees currently held" at the prison.
Accusations of complicity in the US rendition programme have prompted a furious reaction from some of the governments singled out by the report.
The UK, which is accused of complicity in the cases "of several individuals, including Binyam Mohamed, Salahuddin Amin, Zeeshan Siddiqui, Rangzieb Ahmed and Rashid Rauf," rejected the report as "unsubstantiated and irresponsible".
"There is no truth in the suggestion that it is our policy to collude, solicit or participate in abuses of prisoners," a spokesman for the British foreign office said, adding that any debate on the issue "needs to be informed by more than unsubstantiated rumour and allegation".
But the report concludes that secret detention is a reality that needs to be addressed.
"The evidence gathered by the four experts for the present study clearly show that many states, referring to concerns relating to national security - often perceived or presented as unprecedented emergencies or threats - resort to secret detention," it says.
"With very few exceptions, too little has been done to investigate allegations of complicity."