WASHINGTON (AP) — The Senate report at the center of the heated public dispute between Senate Intelligence Committee Chairwoman Dianne Feinstein and the CIA is a detailed investigation of the agency’s rendition, detention and interrogation program that the George W. Bush administration started after 9/11 and which ended in 2009.

— The still-classified report has 6,300 pages, the work of a handful of Democratic Senate investigators who spent four years examining some 6 million pages of CIA and other records. It was approved by the Senate Intelligence Committee in December 2012, and sent to the CIA for comment.