In a Sunday interview with CNN’s Jake Tapper on “State of the Union,” Ronald Kessler, the author of “The Trump White House: Changing the Rules of the Game,” claimed that the President’s counselor and former campaign manager leaks more information to the press than any other individual working in the White House.

Kessler told Tapper that in at least one interview with Conway, she forgot that they were on-the-record as she ripped into her fellow colleagues. According to Kessler, Conway said some of the most “mean, cutting and honestly untrue” things about former chief of staff Reince Priebus, and also “dissed” Ivanka Trump and Jared Kushner, the President’s senior advisor and son-in-law.

“So if you wonder why there are so many leaks out of the White House, one reason is Kellyanne Conway is the number one leaker,” Kessler said.