The scam was so audacious, so outrageous and so clever that it fooled the best and brightest in American publishing.
In 1971, author Clifford Irving convinced McGraw-Hill and Life magazine that Howard Hughes, the reclusive billionaire, had secretly given him permission to write Hughes' autobiography.
Irving was so convincing -- and the publishers so eager -- that they handed over checks totalling close to $1 million. By the time the hoax unraveled, Time magazine had put Irving on its cover as "Con-man of the Year," a title that Irving, now 76 and living in Aspen, Colo., has never quite lived down.
Watch the full interview tonight on "Nightline" at 11:35 EDT
The release of a new movie entitled "The Hoax," after Irving's own memoir, has dredged up a chapter of his life that Irving would just as soon forget.
"I have a list of things I'm called," said Irving, who is played in the film by Richard Gere. "A scam artist, totally reprehensible, con man, flimflam man, a man incapable of the truth, shameless liar and finally, from Richard Gere, 'really not a grown-up.'"
Hughes, of course, was among the most compelling and mysterious characters of his time. The billionaire aviator, movie mogul and industrialist had not been seen in public for 15 years. He was a rich and eccentric hermit. Irving, already a published author, was searching for a new book topic when a magazine article gave him a jolt of inspiration.
Irving says that his researcher, Dick Suskind, and his wife at the time, artist Edith Irving, joined him in hoodwinking his publishers into believing that Hughes had chosen Irving to tell his remarkable life story. At the time, Irving was a relatively obscure writer -- even more astounding, Irving persuaded McGraw-Hill to give him the advance check made out to Hughes.
"You know, one word from your wife, 'That's a stupid idea, you'd go to prison for that,' and it would have been off," Irving said, "but unfortunately when I told her about the idea, she said, 'Oh, that sounds like a lot of fun. Can I be involved? Can I play too?'"
Edith Irving cooked up a disguise and deposited the advance money intended for Hughes into a Swiss bank account. Irving forged Hughes' handwriting, even fooling experts hired by McGraw-Hill.
"I enjoyed writing the book and I got so involved in convincing people that it was real, I went overboard," Irving said. "I think it may also have been a product of the times and the place that I lived in. I lived on an island off the coast of Spain, in the Mediterranean. It was the late '60s, early '70s. It was sex, drugs and rock 'n' roll, and anything goes."
For Irving and his fellow pranksters, keeping up the charade was as exhausting as it was exhilarating.
Their elaborate hoax hinged on one critical condition. "We gambled that Howard Hughes, who was a recluse, would not come out and would not be able to stand up, face a camera, face a judge and say, 'These guys are lying.'"
Hughes never did show his face. But in January 1972, he arranged a conference call with reporters, phoning in from his seclusion in the Bahamas, the last time he would ever be heard from again.
"I don't remember any script as wild. It is as stretching of the imagination as any yarn could turn out to be," Hughes said on the call.
Even after Hughes denounced the project as a fraud, Irving kept the hoax alive.