Clifford Irving walks into federal court in 1972. He fooled publishing executives, Swiss bank officials and lie-detector tests with a phony autobiography of billionaire Howard Hughes. (Jim Wells/AP)

The greatest literary hoax of the 20th century — call it a prank, scandal, ad­ven­ture, criminal conspiracy, or an early piece of “fake news” — fooled lie detectors, handwriting experts, publishers, journalists, Swiss bank officials and very nearly the entire United States.

It featured disguises, an arcane code name (Project Octavio), the world’s most reclusive billionaire and, almost by chance, a president. By some accounts, it may have triggered the Watergate break-in that brought down Richard Nixon.

The hoax’s perpetrator, globe-trotting novelist and Howard Hughes “biographer” Clifford Irving, died Dec. 19 at a hospice near his home in Sarasota, Fla. He was 87 and had been diagnosed last week with pancreatic cancer, said his wife, Julie Irving.

Though known mainly by a small community of writers and artists, Mr. Irving had lived nearly as swashbuckling a life as Hughes when he contacted the publisher McGraw-Hill in early 1971, declaring that he had obtained Hughes’ permission to write a tell-all biography of the aviator and movie mogul.

The son of a prominent New York cartoonist, Mr. Irving had worked as a New York Times copy boy, machinist and door-to-door cleaning supplies salesman before sailing around the world, living on a house boat in India and riding on horseback into Tibet. He wrote novels, reported on the Middle East for NBC and moved to the Spanish island of Ibiza, where he met at least three of his six wives and became a local celebrity, using pictures of Henry Miller and William S. Burroughs for target practice with his BB gun.

Mr. Irving in 1972. (Ray Stubblebine/AP)

His act of literary forgery was inspired by a neighbor on the island, Hungarian art forger Elmyr de Hory, who became the subject of Mr. Irving's book "Fake!" (1968). Sometimes described as a novel — as with much of Mr. Irving's life and work, the lines between fact and fiction were blurred — the book chronicled de Hory's career creating sham works by Picasso, Matisse and Modigliani and inspired the Orson Welles movie "F for Fake."

"All the world loves to see the experts and the establishment made a fool of," Mr. Irving said in Welles's 1973 film essay. "And anyone likes to feel that those who set themselves up as experts are really as gullible as anyone else."

In a letter to his publisher, Mr. Irving said that he had sent a copy of “Fake!” to Hughes, who was reportedly living in near-total isolation inside a hotel in the Bahamas. The billionaire, he said, replied with a thank-you note praising Mr. Irving’s sympathetic treatment of the subject, which Mr. Irving took as an opening to suggest a biography of Hughes himself.

Mr. Irving assumed that Hughes had become so reclusive and private that he would rather stay silent than come forward and deny the book was real. He soon received a staggering $750,000 advance from McGraw-Hill and a sizable check from Life magazine, which planned to publish excerpts from what became known as “Autobiography of Howard Hughes.”

With the help of a researcher and co-author, Richard Suskind, Mr. Irving began studying the details of Hughes's life, gathering old news stories and reference materials. The duo took turns "interviewing" one another, pretending to be Hughes as they transcribed imaginary conversations in which the movie producer described his friendship with Ernest Hemingway (fake) and his efforts to perfectly capture the breasts of actress Jane Russell on film (real).

Mr. Irving traveled to Mexico, Puerto Rico and the Bahamas to “meet” with Hughes in parked cars and motel rooms — much of the time he was actually seeing his mistress, Danish singer and actress Nina van Pallandt — and placed international calls to his publisher to create a heightened air of authenticity.

He studied examples of Hughes’s handwriting to forge letters by the billionaire, encouraging the book’s publication; appeared on “60 Minutes” to try to convince skeptics the biography was real; and was aided throughout by his wife, the former Edith Sommer, who used a false passport to deposit the publishers’ fees in a Swiss bank account under the name H.R. Hughes.

“I’ve read the Hughes manuscript, and it’s good, very good,” she told reporters who visited the Irving family home in Ibiza. “It’s so good it’s a shame it’s an autobiography.”

By late 1971, however, Hughes and his lawyers had apparently had enough of the story and announced the book was fraudulent.

Even then, Mr. Irving nearly succeeded. Hughes had such a reputation for reclusive eccentricity that some journalists theorized that the billionaire, not the writer, was lying. Perhaps, the theory went, Hughes had agreed to be interviewed for the book but later decided that it would compromise his finances and reputation.

The story fell apart entirely in early 1972, just before the book’s scheduled publication, when investigators linked Edith Irving to the Swiss bank account and after van Pallandt announced that she had been with Mr. Irving on some of the dates he allegedly interviewed Hughes.

Mr. Irving, his wife and Suskind returned the remainder of the money they made during the incident and pleaded guilty to charges of grand larceny and conspiracy. Each of them spent time in prison, with Mr. Irving serving about 16 months of a 2½ -year sentence. (His wife was also imprisoned in Switzerland for her role depositing the checks; they divorced after her release.)

Prison time came as a shock to Mr. Irving, who was dubbed “con man of the year” in a Time magazine cover story and insisted that his “autobiography” — called “the most famous unpublished book of the 20th century” by the International Herald Tribune — was merely a joke.

“I don’t see it as a crime worthy of society’s customary revenge,” he later told the reference work Contemporary Authors. “Had I succeeded, no one would have been hurt. . . . If I had it all to do over again, I would do it all, with one difference. I would succeed.”

Clifford Michael Rafsky was born in Manhattan on Nov. 5, 1930. His father, Irving Rafsky, worked in the insurance business before starting a career as a cartoonist. He created the potbellied police character of Pottsy but initially kept his work secret from the family, drawing under the name Jay Irving until he found success doing covers and cartoon strips for Collier's magazine and legally changed his name.

Clifford Irving graduated from Cornell University in 1951 and soon traveled to Europe, where he completed the first of some 20 novels and works of nonfiction, including the legal thriller “Trial” (1990) and “Clifford Irving: What Really Happened” (1972), which was later reissued as “The Hoax.” Written by Mr. Irving and Suskind, the book chronicled the making of their Hughes work, and was adapted into a 2006 movie starring Richard Gere and Alfred Molina.

The film emphasized an unintended and still mysterious aspect of Mr. Irving's hoax: that it may have led to the Watergate burglary. Nixon aide H.R. Haldeman suggested as much in his memoirs, noting — as did White House counsel John Dean in a separate book — that the Nixon administration was concerned that Mr. Irving's biography would reveal undisclosed financial ties between Hughes and the president.

The break-in at the Democratic National Committee headquarters, according to a biography of Hughes by journalist Michael Drosnin, was in large part an attempt to find out how much the Democrats knew about the Hughes connection.

Mr. Irving is survived by his wife of 19 years, the former Julie Schall of Sarasota; three sons from earlier marriages; and one grandson.

Mr. Irving distributed his “Autobiography” online beginning in 1999, and later published it as an e-book. He offered different explanations for why he decided to write it, but eventually pointed journalists toward the epigraph to his book “Hoax,” a quote from someone named Jean le Malchanceux.

“You may look for motive in an act, but only after the act has been committed,” it began. “An effect creates not only the search for a cause, but the reality of the cause itself. I must warn you, however, that the attempt to establish relationships between acts and motives, effects and causes, is one of the most time-wasting games ever invented by Man.”

Mr. Irving told Britain's Telegraph newspaper in 2007 that the quote was from a "12th-century French philosopher" before pausing to correct himself.

“Actually,” he said, “I made him up.”