ALEXANDRIA, Virginia: Former CIA officer John Kiriakou was sentenced Friday to two and a half years in prison for leaking the name of a secret agent implicated in harsh interrogations of Al Qaeda suspects.

Kiriakou, 48, pleaded guilty before a federal court in October to having knowingly disclosed the name of an undercover CIA agent to a freelance reporter, as part of a plea bargain to avoid trial.

Prosecutors argued that Kiriakou betrayed the Central Intelligence Agency and compromised the security of fellow agents, while supporters have hailed him as a whistleblower who exposed harsh interrogation techniques widely viewed as torture.

“Thirty months is way too light,” Judge Leonie Brinkema said sternly as she handed down the sentence.

“This is not a case of a whistleblower. It is about a person who betrayed a very solid trust.”

Had the sentence not been recommended by the prosecution, the judge said she would have imposed a harsher penalty. The 30-month prison term is to be followed by three years of supervised release.

US President Barack Obama's administration has prosecuted six current and former government officials for leaking information — more than all other previous administrations combined — with critics accusing the White House of using anti-spying laws to go after those who expose government malfeasance.

At the same time, the White House has been accused of deliberately leaking information that burnishes its national security credentials, including details of the 2011 raid that killed Osama bin Laden, the Stuxnet cyber-attack on Iranian nuclear facilities and the expanded drone program.

“John is the only CIA agent who will be going to prison with respect to the torture program and he didn't torture anybody,” said Jesselyn Radack of the Government Accountability Project, which helped defend Kiriakou.

Federal Prosecutor Neil MacBride denied any political motives were at work and said the prosecution had nothing to do with the interrogation debate.

“John Kiriakou betrayed the trust bestowed upon him by the US and he betrayed his colleagues, whose secrecy is their only safety,” he said.

Kiriakou worked for the CIA from 1990 to 2004, and made headlines in a 2007 ABC television interview in which he confirmed for the first time that Abu Zubaydah, a top Al Qaeda detainee, had been subjected to waterboarding.

The interrogation technique, a form of simulated drowning, was used on a number of Al Qaeda suspects during the George W. Bush administration but has been widely denounced as torture and was halted by Obama.

Kiriakou admitted to giving secret information about two CIA agents to two reporters between 2007 and 2009, according to court documents.

The name of one agent later came into the possession of a lawyer for a “high-value” detainee at Guantanamo Bay, the US prison compound used for Al Qaeda suspects swept up in the early years of the so-called war on terror.

But Kiriakou's lawyer, Robert Trout, said his client was concerned about the interrogation practices and had no intention to cause harm to the United States or any person.

“He gave names with that expectation, that they be contacted and may choose to speak about it. Naively, he didn't appreciate that he could lose control of it,” he said.

Former CIA agent Glenn Carle told AFP Kiriakou had “made a mistake” but did not deserve jail time, calling his prosecution along with those of other government officials “a recent and chilling development in American history”.

Kiriakou himself struck an upbeat tone, saying he was “positive, confident and optimistic” after being sentenced for a crime to which he had pleaded guilty.