By Mark Hosenball and Warren Strobel
WASHINGTON (Reuters) - The White House's top lawyer has tried to mediate between the Senate Intelligence Committee and the CIA, which are making increasingly bitter mutual charges of spying on each other about a Bush-era program of harsh interrogation, a source familiar with the discussion told Reuters.
The involvement of Counsel Kathryn Ruemmler indicates White House interest in ending the battle, in which the Central Intelligence Agency and the Senate panel have essentially accused each of spying on the other.
Ruemmler has attempted to "de-escalate" the tension, the source said. The fight burst into the open on Monday when the committee chair Democratic Senator Dianne Feinstein said the CIA had possibly broken the law by spying on Congress.
CIA Director John Brennan denied that the spy agency had engaged in such activities, saying "Nothing could be further from the truth."
Feinstein accused the agency of searching computers used by committee staffers examining CIA documents when they were researching counter-terrorism operations and the use of harsh interrogation methods such as simulated drowning or waterboarding.
The issue has escalated into a major fight over the interrogation program, which President Barack Obama halted shortly after taking office in 2009, and over the powers of the executive and legislative branches.
At the heart of the dispute is a Senate review of the CIA program which was put in place after the September 11, 2001 attacks and included interrogation methods which critics say were a form of torture banned by international law.
White House spokeswoman Jay Carney said Obama wanted to see the review completed and declassified for public release.
"I think setting aside those matters, the president's focus and the White House's focus is on ensuring that the committee is able to complete its work and that it does so expeditiously; that it submits that report for declassification, a request for declassification, which has not been made yet," he said.
White House Chief of Staff Denis McDonough and Ruemmler have been in touch with Republicans and Democrats about the review to get both it and minority Republicans' dissenting views declassified, National Security Council spokeswoman Caitlin Hayden told Reuters in an email.
(Additional reporting by Doina Chiacu; Editing by Alistair Bell and Phil Berlowitz)