WASHINGTON (AFP) - Pentagon documents released by rights groups have detailed the agency's involvement in "war on terror" excesses, fuelling debate over possible probes into the administration of former president George W Bush. After more than four years of legal wrangling, the groups - Amnesty International USA (AIUSA), the Centre for Constitutional Rights (CCR), and the Centre for Human Rights and Global Justice (CHRGJ) - obtained the documents through the Freedom of Information Act (FoIA). The US Department of Defence (DoD) papers reveal details of secret prisons in Afghanistan and Iraq, and "affirm the DoD's cooperation with the CIA's ghost detention programme," according to the group's statement. "It is increasingly obvious that defence officials engaged in legal gymnastics to find ways to cooperate with the CIA's activities," said Margaret Satterthwaite, Director of the NYU International Human Rights Clinic. In one of the internal papers, from late May 2004, officials discuss how rights ensured by the Geneva Conventions were essentially waived for some detainees in Iraq. "Ghosting" of detainees occurred by prohibiting visits by the International Committee of the Red Cross, said the groups at a Press conference Thursday. In another example, an internal DoD email from February 17, 2006 reveals how a scheduled release of unnamed Guantanamo Bay detainees was postponed for public relations reasons. The message recommends "hold[ing] off on return flights for 45 days or so until things die down. Otherwise we are likely to have hero's welcomes awaiting the detainees when they arrive." Referring to this email, Pentagon spokesman Jeffrey Gordon said the documents were "part of an internal communications process to safely transfer detainees overseas, and did not reflect a statement of DoD policy". In a separate FoIA request released this week, the American Civil Liberties Union highlights a report by Vice Admiral Albert Church, who conducted a review of DoD interrogation practices, that detail how two detainees died from their treatment. "Interrogations in both incidents involved the use of physical violence, including kicking, beating, and the use of 'compliance blows' which involved striking the [prisoners] legs with the [interrogators] knees. "In both cases, blunt force trauma to the legs was implicated in the deaths." According to Amnesty's Policy Director for Counterterrorism, Terrorism and Human Rights, Tom Parker, the documents represent "the tip of the iceberg". A majority of the hundreds of pages amount to news articles and Press statements, but the groups maintain they will continue to investigate the practices. "We want information about who knew what of the programme, and when. Who authorised what and when. And we also want to know who has disappeared in this programme," said Satterthwaite. CCR President Michael Ratner echoed sentiments of the other rights groups by calling for an investigation. "If crimes have been committed, and there is ample evidence that they have, then the people who committed those crimes should be prosecuted. "It's as simple as that," he said. Two leading Democrats, House Judiciary Committee chairman John Conyers and Senate Judiciary Committee chairman Patrick Leahy have proposed commissions to investigate possible violations. At a Press conference this week President Barack Obama expressed reticence about a probe, saying it was time to move forward, though he did not rule out possible prosecutions. "My view is also that nobody is above the law," he said. "If there are clear instances of wrongdoing, that people should be prosecuted just like any ordinary citizen." In a bid to obtain further proof of Bush involvement in the controversial CIA practices, Parker called the new Attorney-General, Eric Holder, and other officials in the Obama administration to "work actively to comply with FOIA requests."