In an open letter to the Pope, Sabrina De Sousa said imposition of state secrets ensure that abuses of power are never exposed.
An Indian-origin former CIA official, being extradited to Italy to serve a jail term for her alleged role in the 2003 abduction of an Egyptian cleric, has appealed to Pope Francis to speak out against the extraordinary renditions used by the spy agency post 9/11 attacks.
In an open letter to the Pope, Sabrina De Sousa said imposition of state secrets on the Rendition, Detention and Interrogation programme, ensure that abuses of power or human rights are never exposed.
"State secrets, as I discovered, are also used to hinder proper investigations," said De Sousa, who is to be extradited from Portugal to Italy to serve a four-year sentence after Portugal's Constitutional Court rejected her final appeal.
Observing that the Pope has spoken decisively about the programme, she said: "We need Your Holiness' voice now more than ever to keep this issue in the forefront for much-needed discourse in the court of public opinion. If we do not have a complete understanding of the impact and utility of such programmes, it's entirely possible that similar programmes will in the near future be introduced in the name of national security."
De Sousa, 60, has a dual citizenship of Portugal and the US. She is being extradited for her alleged role in the February 2003 rendition of Hassan Mustafa Osama Nasr, also known as Abu Omar.
De Sousa, who grew up in Mumbai, was among 26 Americans convicted in absentia by Italian courts for their alleged role in the abduction.
"As of today, my extradition from Portugal to Italy is underway. Italy has guaranteed Portugal that I will be notified of my sentence and have the opportunity to counter the charges against me. Whether that happens, remains to be seen," De Sousa wrote in her letter.
She said she was a US government official and diplomat accredited to Italy at the time of the Abu Omar rendition.
"I was charged and convicted in absentia for his kidnapping, charges that I have tried to counter for over a decade. I was never notified nor was I allowed to defend myself because of secrecy obligations.
"My attempts over several years to engage senior US officials and members of the Intelligence committees in the Congress of the US also proved fruitless," she said.
"The absence of due process and the imposition of various versions of state secrets are obstacles that prevent the many unanswered questions about the premise and justification for Abu Omar's rendition," De Sousa said.
These same obstacles are emblematic of the fact that even after a decade the stated objective of "bringing terrorists to justice" has yet to take place, said the former CIA official.
"When these abuses are exposed by a few courageous citizens, retribution is swift. Lives are destroyed, families threatened and many are imprisoned for the crime of exposing criminal conduct.
"Further, the insertion of secrecy within a system which was meant to allow citizens the ability to voice legitimate concerns before elected officials, renders the system useless," De Sousa said.