US General David Petraeus gestures during the Senate Intelligence Committee hearing on his nomination to be director of the Central Intelligence Agency on Capitol Hill in Washington in this June 23, 2011, file photo. [Photo/Agencies]

WASHINGTON - Former CIA director David Petraeus told reporters that he had made "big mistakes" in the newly disclosed scandal but never passed any classified information to his biographer with whom he had an extramarital affair that led to his shocking resignation, CNN reported on Thursday.

Petraeus made his first comments since the announcement of resignation last Friday to CNN reporter and anchor Kyra Phillips. Phillips said the retired four-star general insisted that he had not passed any classified information to Paula Broadwell, his biographer in the center of the scandal that has become an uproar in Washington over the past week.

"In our first conversation, he had told me he had engaged in something dishonorable, and he sought to do the honorable thing in response, and that was to come forward," said Phillips. "He was very clear that he screwed up terribly, and that was all his fault, even he felt fortunate to have a wife who is far better than he deserves."

Petraeus also denied the resignation was linked to the attack on the US Consulate, Benghazi, Libya that killed four Americans in Sept 11. "He said this has nothing to do with Benghazi, and he wants to testify. He will testify," said Phillips.

The former CIA director is set to testify before the US House Intelligence Committee about the Benghazi attack.

Petraeus, a retired general who served more than 37 years in the US Army, took the office as CIA director in September, 2011. He had overseen all coalition forces in Iraq and led the military campaign in Afghanistan.

Media reports said the FBI (Federal Bureau of Investigation) began investigating the case after Jill Kelley, a friend of the Petraeus family, complained to law enforcement about receiving anonymous and threatening emails. The FBI traced the emails to Broadwell and then discovered that Broadwell was Petraeus' girlfriend.

US lawmakers on both sides have criticized the FBI for not notifying the Congressional intelligence and security panels of the probe into Petraeus's scandal.

US President Barack Obama said Wednesday that he has "no evidence" that the sex scandal of Petraeus has had a negative impact on the US national security.

Kelley, a social liaison at MacDill Air Force Base, Florida, was also reported to have close relations with both Petraeus and John Allen, top commander of the US troops and International Security Assistance Force in Afghanistan.

Earlier Tuesday, Defense Secretary Leon Panetta announced that Allen is also being investigated for alleged "inappropriate communications" with Kelley. Due to the pending investigation, Allen's nomination to the NATO commander has been put on hold.