On Tuesday, the head of the Senate Intelligence Committee sharply criticized the CIA, saying the agency had improperly interfered with one of the panel’s most sensitive investigations. The comments by Chairman Dianne Feinstein (D-Calif.) marked an extraordinary — and extraordinarily public — turn in a long-simmering dispute between lawmakers and the intelligence agency.

Some details of the back story:

What is this Senate report that has Congress and the CIA feuding in such a public way?

In 2009, the Senate Intelligence Committee began an exhaustive review of the CIA’s erstwhile detention and interrogation program. The program used harsh tactics such as waterboarding, or simulated drowning, to elicit information from terrorism suspects held at secret prisons overseas.

Senate Intelligence Chair Dianne Feinstein (D-Calif.) accused the CIA of breaking the law by searching her committee's computers. The Post's Karen Tumulty, Scott Wilson, Terence Samuel and Adam Goldman explain the impact in Washington. (Julie Percha and Theresa Poulson/The Washington Post)

What does the report say?

According to U.S. officials, the 6,000-page report shows that the CIA misled Congress, the White House and the Justice Department and overstated the program’s success before President Obama ended it in 2009. Details of the report have not been made public. Feinstein said it’s “by far the most important oversight activity ever conducted by this committee.”

Why hasn’t the report been declassified and released?

In 2012, the committee voted to approve the study of the program and sent it to the CIA for comment. The agency has asked for corrections in a 122-page response. The committee must vote again on a final version of the report. On Tuesday, Feinstein told reporters that she hopes to make a motion this month to declassify the report on the interrogation program.

What caused the latest blowup between the committee and the CIA over the report?

The CIA said the committee took certain documents from a secret facility in Northern Virginia without its permission. This prompted the agency to search the Senate computers without the panel’s knowledge. Feinstein said the committee was fully entitled to the documents and didn’t take them without the agency’s permission. This has caused a showdown, with each side asserting it is in the right.

What will happen next?

The CIA has referred the incident to the Justice Department and the agency’s inspector general has opened an investigation.