President Donald Trump's nominee to be the CIA's independent watchdog has told Congress that he's never read the Senate's so-called torture report, an exhaustive, classified report of the agency's treatment of terror suspects after 9/11.

Christopher Sharpley, who has been deputy inspector general at the CIA since July 2012, told the Senate intelligence committee Tuesday that the classified disc containing the 7,000-page report was lost for a time and later found, but that he never took time to read the full document.

The Senate intelligence committee spent years investigating the CIA's detention and harsh interrogation techniques on suspected terrorists captured by the United States after the Sept. 11, 2001, attack on U.S. soil. The techniques authorized by the Bush administration included waterboarding. Interrogations were conducted in clandestine prisons around the world that were not in the jurisdiction of U.S. courts or the American military justice system.

Democrats scolded Sharpley during his confirmation hearing, saying he should have read and learned from the report because the inspector general's job involves oversight of covert CIA activities.

Committee members also quizzed him about his commitment to protecting whistleblowers who report waste, fraud and abuse at the agency and how they need to be shielded from retaliation.

Sen. Dianne Feinstein, D-Calif., read from a February document on the official letterhead of the Office of the Inspector General of the Intelligence Community that describes flaws in the way that retaliation cases are investigated. The document was disclosed by the Project on Government Oversight, which reported on Monday that Sharpley is named in three open whistleblower retaliation cases.

Sharpley defended his record, saying he has never retaliated against anyone in the inspector general's office or at any other federal agency.

Sen. Susan Collins, R-Maine, commended him for being a productive inspector general, saying his office has conducted more than 100 audits and inspection reports and issued more than 340 recommendations in the past year to help improve the agency's efficiency and effectiveness.

She also cited his work on countering insider threats from employees who have disclosed "devastating amounts" of classified information. Sharpley said his office has issued more than two dozen reports and made 64 recommendations addressing insider threats.

The CIA has "done a lot on insider threats, but a lot more work needs to be done," he said.

Democrats on the committee spent most of their time during the confirmation hearing questioning him about the torture report.

"The point of distributing it to the departments was in the hope that they would read it — not look at it as some poison document — and learn from it," said Feinstein, who was chairman of the committee when it was released.

Sen. Martin Heinrich, D-N.M., noted that the inspector general's job involves overseeing covert activities. "It seems to me that it's awfully hard to learn the potential lessons of that report, if it wasn't consumed and read and processed in your office," Heinrich said.

Heinrich acknowledged that Sharpley did read summaries of the report, but said there were chapters in the much longer, classified version that dealt specifically with the operations of the inspector general's office, which could be instructive to the person leading that office.

Sen. Ron Wyden, D-Ore., said he would oppose his confirmation over the issue.

The committee is expected to vote next week.

Sharpley said the CIA received the report in December 2014 and it was uploaded to the inspector general's classified system. Shortly thereafter, the CIA was told to delete it from the agency's system because of an ongoing Freedom of Information Act court case. The CIA was instructed to put the report on a disc and place it in a classified safe.

Several months later, Sharpley said he asked for the disc, but nobody could find it. He initiated an investigation and an information technology employee said it had been shredded.

Several months later, a retiring employee sifting through his materials found the disc in a classified safe. Sharpley said the employee who said he had shredded it was re-interviewed. This time, the individual, who had by then left the CIA, said he didn't actually remember shredding that specific disc, but that he had a stack of media on his desk and thought he had shredded it.

"It's embarrassing and I have apologized," Sharpley said.

He said this occurred around the same time that the courts ruled that the report was a congressional document and Sen. Richard Burr, R-N.C., had requested copies that had been distributed to intelligence and other executive branch agencies be returned to the committee. Democrats criticized Burr for that request, accusing him of trying to bury the document.

"I made an independent judgment to return the disc," Sharpley said, adding that his decision was not a reflection on the quality of the report or its importance to history.

"I did not have an opportunity to read the report," Sharpley said, although he acknowledged that he could have read it before he returned it to the committee, but chose not to do so.