Mr. Kiriakou had played a significant role in some of the C.I.A.’s major achievements after the attacks of Sept. 11, 2001. In March 2002, he led a group of agency and Pakistani security officers in a raid that captured Abu Zubaydah, who was suspected of being a high-level facilitator for Al Qaeda.

In 2007, three years after he left the C.I.A., Mr. Kiriakou discussed in an interview on ABC News the suffocation technique that was used in the interrogations known as waterboarding. He said it was torture and should no longer be used by the United States, but he defended the C.I.A. for using it in the effort to prevent attacks.

In subsequent e-mail exchanges with a freelance writer, Mr. Kiriakou disclosed the name of one of his former colleagues, who was still under cover and had been a part of the detention and interrogation program.

The freelancer later passed the name of the undercover agent to lawyers representing several Qaeda suspects being held at Guantánamo Bay, Cuba.

The lawyers later included the name in a sealed legal filing, angering government officials and kick-starting the federal investigation that ultimately ensnared Mr. Kiriakou. The name was not disclosed publicly at the time, but it appeared on an obscure Web site last October. In January 2012, federal prosecutors indicted Mr. Kiriakou, accusing him of disclosing the identity of an agency analyst who had worked on the 2002 raid that led to Abu Zubaydah’s capture and interrogation.

The prosecutors said Mr. Kiriakou had been a source for a New York Times article in 2008 written by Scott Shane that said a C.I.A. employee named Deuce Martinez had played a role in the interrogation. When Mr. Kiriakou pleaded guilty last October, the charges stemming from that disclosure were dropped along with several others.

Prosecutors raised questions this week about Mr. Kiriakou’s contrition. In a filing, prosecutors cited a lengthy article by Mr. Shane published this month in The Times in which he quoted Mr. Kiriakou as saying that if he had known that the C.I.A. officer was still under cover, he would not have disclosed his identity.

The prosecutors said that Mr. Kiriakou’s intimation that the disclosure was an “accident or mistake” contradicted his plea that he had willfully disclosed the information.