We may be finally learning more about the CIA's involvement in the 2003 abduction and rendition to torture of a Muslim cleric, Hassan Mustafa Nasr (aka Abu Omar). This week, Sabrina De Sousa confirmed that she was a former CIA undercover officer, and provided new details about events that led to the first (and, to date, only) prosecutions and convictions for abuses committed by U.S. officials as part of its "extraordinary rendition" program. Her account highlights the desperate need for the United States to thoroughly investigate the role of government officials in acts of torture and extraordinary rendition committed in the years following 9/11.

In 2003, CIA agents seized Abu Omar from the streets of Milan, Italy and rendered him to Egypt for interrogation and torture by Egyptian officials. He was later released without charge or trial.

In September 2012, Italy's highest court affirmed the in absentia convictions of 23 Americans, including De Sousa, and two Italians involved in Abu Omar's kidnapping and torture. The ACLU opposes trials in absentia, which raise serious due process concerns; the Italian proceedings serve as a reminder, however, of the lack of accountability in the United States for CIA abuses. De Sousa, who was sentenced by the Italian court to seven years in prison, had previously denied any involvement with the CIA, claiming instead that she was a State Department employee and that she should have been granted diplomatic immunity from prosecution.

De Sousa now admits that at the time of the extraordinary rendition, she was a CIA agent and involved in the rendition as a translator between the CIA snatch team and their Italian counterparts. Incensed for "being held accountable for decisions that someone else took," De Sousa has provided shocking – but by no means surprising – details about the extraordinary rendition operation in a series of recent interviews with McClatchy Press.

De Sousa revealed that the former CIA station chief in Rome, Jeffrey Castelli, had exaggerated the threat Abu Omar posed in order to win approval for the extraordinary rendition, and misled his superiors into believing that Italian military intelligence had agreed to the operation. She also claims that the extraordinary rendition was approved at the highest levels of government despite doubts about the threat Nasr posed; those involved in the decision-making process, she says, included former CIA director George Tenet; Condoleezza Rice, who was national security advisor at the time; and then-President Bush. (Among those convicted, Robert Lady, the CIA's former Milan station chief, was sentenced in absentia to nine years for his involvement in the rendition; read De Sousa's account for more on his case.)

De Sousa's revelations highlight the need for greater transparency and accountability by the United States government for the torture and abuse that occurred during the Bush administration. Criminal investigations initially opened into specific allegations of abuse have all been closed and the government has consistently shut down attempts to challenge its actions in court through claims of state secrets and immunity. Other nations, such as Italy, however, have taken a different approach.

Click here to learn how different countries have pursued accountability for their roles in the U.S. torture and rendition program.

In addition, the European Court of Human Rights recently agreed to consider a second case against Poland over allegations from another former CIA prisoner, Zayn al-Abidin Muhammad Husayn (known as Abu Zubaydah), who was tortured while held in a secret CIA-run prison in Poland. While these measures are an important step in ensuring accountability for U.S. actions on the global stage, they do not absolve the U.S. from its own responsibility under international law to hold those who were responsible for CIA abuses accountable, and release information about the unlawful activities carried out as part of the extraordinary rendition program. An important starting point should be the declassification and publication of the Senate Select Intelligence Committee report , the only official account of the CIA's torture and abuse. De Sousa may have provided important information on one specific extraordinary rendition, but we need far more to ensure that abuses committed by the United States are fully brought to light.