The Senate Intelligence Committee has released a blistering, 500-page report on the CIA's controversial detention and interrogation program, a document that committee chairwoman Dianne Feinstein said represents the most significant oversight effort in the history of the US Senate.

The $40 million, five-year study concluded that CIA officials exaggerated the value of the intelligence they gleaned from dozens of "high-value detainees" held at black site prisons, where they were subjected to so-called "enhanced interrogation techniques" such as sleep deprivation and waterboarding.

The committee reviewed more than 6 million pages of top-secret CIA documents and found that the architect of the interrogation program was a retired Air Force psychologist named James Mitchell, an agency contractor who — according to news reports — personally waterboarded alleged 9/11 mastermind Khalid Sheikh Mohammed. The Senate report does not identify Mitchell by name.

Mitchell has a signed a non-disclosure agreement with the CIA and was unable to discuss his alleged role in the agency's enhanced interrogation program, but VICE News met up with him in suburban Florida to discuss the Senate's report and one of the darkest chapters of the war on terror. This is the first time Mitchell has ever appeared on camera.

UPDATE: One day after this video was released, James Mitchell confirmed to VICE News that he that he was under contract to the CIA after 9/11 and that he was "part" of the enhanced interrogation program. This marks the first time Mitchell has acknowledged his role in the program.

Editor's note: One week after this video was released the restrictions on Mitchell's non-disclosure agreement were loosened. In an exclusive follow-up interview with VICE News, Mitchell admitted that he was the interrogator who personally waterboarded Khalid Sheikh Mohammed, al Qaeda facilitator Abu Zubaydah, and Abd al-Rahim al-Nashiri, the accused mastermind behind the USS Cole bombing. 

Read "Community Outreach — Not 'Enhanced Interrogation' — Might Be the Best Way to Stop Terror Attacks"

Read "What $300 Million Bought the CIA's 'Detention and Interrogation' Program"

Read "Senate Torture Report Finds the CIA Was Less Effective and More Brutal Than Anyone Knew"

Read "UN Official Wants US Administrators Involved in Torture to Be Prosecuted"

Subscribe to VICE News on YouTube

Follow VICE News on Twitter

Like VICE News on Facebook