The Federal Bureau of Investigation (FBI) is investigating whether staff members for the Senate Intelligence Committee removed classified documents without authorization for use in a committee report criticizing the Central Intelligence Agency's (CIA) interrogation techniques, McClatchy Newspapers reported on Thursday.

The FBI's probe was instigated by a request from the office of the CIA's general counsel to the Justice Department, stating that committee staffers took the documents from a secured reading room used for reviewing top-secret documents, including emails.

CIA Inspector General David Buckley office also sent a separate criminal referral to the Justice Department regarding the agency's supervision of the computers used by Intelligence Committee staff for reviewing classified documents at an agency facility in Virginia.

As the New York Times and MSNBC reported on Wednesday, the CIA and the committee have clashed for months regarding a 6,300-page report that is said to be highly critical of the agency's "enhanced interrogation" practices during then-President George W. Bush's administration.

The study cost $40 million to compile and documented CIA practices, which included waterboarding in secret prisons in multiple continents. The report concluded that the agency failed to glean much in the way of valuable intelligence during those interrogations, which were stopped by President Barack Obama not long after he took office in 2008.

According to McClatchy, committee staff came upon information in the fall of 2013 alleging that a draft of an internal CIA review commissioned by ex-Director Leon Panetta agreed with the report's findings. However, the CIA's official response to the report questioned some of the report's findings, a discrepancy which staff members felt was misleading to lawmakers.

[Image via Agence France-Presse]