WASHINGTON // Barack Obama had hoped to close a chapter and move on, after publicising details of the controversial techniques the Bush administration sanctioned in the name of extracting information from terror suspects. Instead, the US president has opened a new one - marked by renewed calls for investigation from rights groups and congressional Democrats, vigorous debate over whether the tactics were effective or necessary and recriminations by some Republicans who say Mr Obama clearly does not understand the threats facing this nation.

The memorandums made public last week have provided more fodder, not less, for those hoping Bush-era officials will be prosecuted for the use of tactics Mr Obama has since banned - including one, waterboarding, his administration considers illegal torture. Yesterday, representatives from groups including the American Civil Liberties Union and moveon.org were set to deliver petitions containing more than 250,000 signatures to Eric Holder, the attorney general, in support of the call for the appointment of an independent prosecutor. Mr Holder was due to testify on Capitol Hill at a hearing unrelated to the interrogation issue.

Even Mr Obama, who has long been cool to the idea of an investigatory commission and who said just days ago that "nothing will be gained by spending our time and energy laying blame for the past", has reopened the door to just such a panel, possibly modelled after the independent bipartisan 9/11 commission. The president and Mr Holder announced last week that rank-and-file CIA officers who used the aggressive tactics would not face government charges, because the Bush justice department had deemed them legal. It was unclear at the time of that announcement whether higher-level officials might face charges, and the administration has been sending mixed signals.

Seemingly wanting to distance himself from the process, Mr Obama is now stressing that any decision on prosecuting the attorneys who provided the legal framework for the use of the techniques would be left to Mr Holder. Meanwhile, a report by the Senate armed services committee, one of several on past interrogation practices declassified and made public in recent days, has challenged the claim of Bush-era officials that the prisoner abuse that occurred in places such as Iraq's Abu Ghraib prison was simply the work of a few "bad apples". It was, rather, the report found, a direct result of policies fashioned at the highest levels of the Bush administration.

Carl Levin, the panel's Democrat chairman, said this week the report "represents a condemnation of both the Bush administration's interrogation policies and of senior administration officials who attempted to shift the blame for abuse such as that seen at Abu Ghraib, Guantanamo Bay and Afghanistan to low-ranking soldiers". "Claims ? that detainee abuses could be chalked up to the unauthorised acts of a 'few bad apples' were simply false," Mr Levin said. "Authorisations of aggressive interrogation techniques by senior officials resulted in abuse and conveyed the message that physical pressures and degradation were appropriate treatment for detainees in US military custody."

That report has led the lawyer for one soldier convicted in connection with Abu Ghraib, Charles Graner, to say he will seek a presidential pardon for his client. Mr Graner is serving a 10-year sentence. Janis Karpinski, a former brigadier general who was another central figure in the Abu Ghraib scandal, also spoke out this week, saying the information emerging now supports the charge she has long made: she and the lower-ranking soldiers who faced charges were scapegoats.

"From the beginning, I've been saying that these soldiers didn't design these techniques on their own," Ms Karpinski, who was demoted to colonel, told CBS's The Early Show. "The line is clear: it went from Washington, DC, from the very top of the administration with the legal opinions, through Bagram [Air Force Base in Afghanistan] to Guantanamo Bay and then to Iraq via the commander from Guantanamo Bay, Cuba."

Another report, by the Senate intelligence committee, revealed that top Bush officials, including Condoleezza Rice, the national security adviser in Mr Bush's first term, sanctioned the use of waterboarding as far back as 2002. On Wednesday, three senators, including John McCain, last year's Republican nominee for the White House, wrote to Mr Obama to argue against what they called the criminalisation of legal opinions. They called for the president to do what he himself has many times said he wants: look forward.

"Moving in such a direction would have a deeply chilling effect on the ability of lawyers in any administration to provide their client - the US government - with their best legal advice," Mr McCain wrote along with Joseph Lieberman, a Connecticut independent, and Lindsey Graham, a South Carolina Republican. "Pursuing such prosecutions would, we believe, have serious negative effects on the candour with which officials in any administration provide their best advice, and would take our country in a backward-looking direction at a time when our detainee-related challenges demand that we look forward."

A full accounting of who knew what about the interrogation techniques, and when, would not include just former Bush officials; top members of Congress were briefed on the programme along the way as well. eniedowski@thenational.ae