Cartha D. DeLoach, who as a top aide and confidant to J. Edgar Hoover was the F.B.I.’s liaison to the White House and a powerful intermediary between Hoover and President Lyndon B. Johnson during an especially tense political era, died on Wednesday on Hilton Head Island, S.C. He was 92.

The death was confirmed by his son Tom.

Mr. DeLoach, who was known as Deke, spent more than 25 years in the Federal Bureau of Investigation, rising to deputy associate director, the No. 3 position, behind only Mr. Hoover and the associate director, Clyde Tolson.

Mr. DeLoach had met and worked with Johnson in the 1950s, when Johnson was the Senate majority leader; he and Johnson helped push through legislation guaranteeing Hoover a salary for life. In 1963, shortly after President John F. Kennedy was assassinated, Johnson called Hoover — Mr. DeLoach said it was the day after Johnson was sworn in aboard Air Force One — and requested that Mr. DeLoach be assigned to the White House....