WASHINGTON (AP) ― The head of the U.S. Senate Intelligence Committee accused the CIA on Tuesday of criminal activity in improperly searching a computer network set up for lawmakers investigating allegations that the agency used torture in terror investigations during the Bush administration.

Democrat Dianne Feinstein, in an extraordinary speech on the Senate floor, publicly aired an intense but formerly quiet dispute between Congress and the spy agency. She said the matter has been referred to the Justice Department for further investigation.

Feinstein’s accusation is the latest storm to hit the U.S. intelligence community, which has been reeling from former NSA systems analyst Edward Snowden’s revelations about its mass surveillance programs.

While the monitoring outlined by Feinstein appears far more limited than in the NSA scandal, the backlash could be significant because it involved the panel that oversees the CIA’s programs and funding.

The criticism by Feinstein is particularly biting because she has been one of the main defenders of intelligence agencies at a time that they have been sharply criticized at home and abroad. Feinstein said she has sought an apology but said the CIA has been silent.

CIA Director John Brennan, asked about Feinstein’s accusations, said the agency was not trying to stop the committee’s report and that it had not hacked into Senate computers. He said the appropriate authorities would look at the matter further and “I defer to them to determine whether or not there was any violation of law or principle.”

The White House said President Barack Obama agrees with Brennan that it’s important to get to the bottom of whether the spy agency committed violated any laws with respect to a Senate panel’s investigation. White House spokesman Jay Carney did not take sides between the CIA and Feinstein. He said can’t comment because there‘s an ongoing review by an inspector general and that the matter has also been referred to the Justice Department.