Washington ? Fred LaRue, the shadowy Nixon White House aide and “bagman” who delivered more than $300,000 in payoffs to Watergate conspirators, died of coronary artery disease in a Biloxi, Miss., motel room, where he lived. He was 75.

His body was found by a motel maid Tuesday, but Harrison County, Miss., coroner Gary Hargrove said he believed the death occurred Saturday. LaRue had a history of heart problems, Hargrove said.

Considered one of the most mysterious men in the Nixon administration, LaRue served as a presidential aide without title, salary or mention in the White House directory. Yet he was so close to the center of power that he was one of the few present at a March 30, 1972, meeting at Nixon’s vacation home on Key Biscayne, Fla., at which former attorney general John Mitchell discussed the planned break-in and bugging of the Democratic National Committee headquarters office in the Watergate building.

Born in Athens, Texas, LaRue was nicknamed “Bubba” in his family and graduated from the University of Oklahoma with a bachelor’s degree in geology in 1951. He came to Washington in 1969.

The money for the operation came from Nixon’s re-election campaign funds, as did “hush money” paid to the Watergate burglars and their attorneys, LaRue later testified to the Senate Watergate investigative committee. He was the first administration official to plead guilty to charges in the Watergate cover-up, and was the last to be sentenced. He pleaded guilty to one count of conspiracy to obstruct justice and was sentenced to one to three years, with all but six months suspended. He served 136 days.

After LaRue pleaded guilty and served his sentence in 1973, he returned to Mississippi, where he worked in the family oil and real estate development business, his nephew William T. LaRue said. The family money had dwindled by the early 1970s, after the LaRues lost money in the Castaways, a Las Vegas gambling casino they bought in 1963. LaRue said in 1971, “I’m no millionaire.”

He was one of many Nixon-era figures rumored over the years to be “Deep Throat,” the source of Washington Post reporters Bob Woodward and Carl Bernstein. LaRue denied that he was Deep Throat, and Woodward said he will not reveal the source’s name until after Deep Throat dies.

Survivors include his wife, Joyce LaRue of Jackson, Miss.; five children; and several grandchildren.