Senior Central Intelligence Agency officials, including the London station chief, have been brought before a grand jury in Virginia investigating the potentially illegal destruction of 92 video tapes recording the torture and interrogation of al-Qaida detainees.
A special prosecutor, John Durham, has called the CIA officials as part of an 18-month-long criminal probe in to the destruction of evidence of the agency's interrogators using waterboarding and other forms of torture against Abu Zubaydah and Abd al-Rahim al Nashiri who are described by the Americans as "high value" detainees now held at Guantánamo Bay.
Those ordered to testify include the former CIA chief, Porter J Gross. Another is a woman who is not publicly named who heads the agency's London station. She previously worked as the chief of staff for the head of the CIA's clandestine branch, Jose Rodriguez, who is the focus of the investigation.
The New York Times reports that former CIA officers have identified the woman as having helped carry out Rodriguez's order to destroy the tapes which had been kept in a safe in at the agency's station in Thailand where the torture and interrogations were carried out.
Rodriquez is reported to have been concerned that agents might have been identified and endangered if the tapes leaked.
But the CIA will also have been concerned that some of its agents may have been open to prosecution under domestic and international laws against torture besides the enormous damage to its already battered reputation if video were made public of the extended torture and brutal techniques used against the captives. The impact is likely to have been much greater than the outcry caused by the pictures of abuse by US soldiers at Baghdad's Abu Ghraib prison.
President Obama has since pledged not to prosecute individual agents for their part in torture and interrogations because they were assured by the Bush administration that their actions were legal.
The investigation was launched because the destruction of the tapes may amount to a criminal offense because it was evidence that could have been used in any prosecutions for torture. Robriquez has told colleagues that he received legal guidance from CIA lawyers who told him he had the authority to order the destruction of the tapes.
However it remains open to question whether anyone will be brought to trial for that or other alleged offenses given the Obama administration's desire to reassure CIA agents that they will not be pursued over past crimes.
The existence of the tapes was only made public after they were destroyed.
On Thursday, the Obama administration said it will delay until the end of next month the release of a 2004 CIA report detailing the torture and other abuse of prisoners held in clandestine prisons oversees.