A FORMER CIA officer has been sentenced on Friday to 30 months' jail for disclosing classified information to journalists in a case that underscored the Obama administration's harsh crackdown on national security leaks.

John Kiriakou, a 14-year CIA veteran, pleaded guilty in October to identifying an undercover operative who was involved in the use of severe interrogation techniques, including waterboarding, under the George W. Bush administration.

Jailed ... CIA veteran John Kiriakou. Credit:AP

While the Justice Department has said it will not prosecute CIA officials who approved or conducted those interrogations, Kiriakou becomes the sixth current or former official charged with revealing classified information since 2009.

His lawyers and civil rights advocates portrayed the 48-year-old former counterterrorism officer as a whistleblower who helped expose torture in secret prisons. The CIA and its defenders denied using torture, which is illegal, referring to enhanced interrogation techniques.