The famed magician Harry Houdini guarded the secrets behind his legendary escapes from handcuffs, chains, jails, milk cans, mailbags, and water chambers. But the authors of a forthcoming book on Houdini will be disclosing that he had another secret: his role as a spy. This claim is already causing a stir in the magic community and will create more buzz on October 31 — exactly 80 years after Houdini’s death at age 52 — when William Kalush and Larry Sloman’s “The Secret Life of Houdini: The Making of America’s First Superhero” rolls off the presses.

The authors argue that intelligence agencies on both sides of the ocean likely employed the Hungarian-born showman. The book notes that Houdini canceled profitable contracts and abruptly headed to Europe in 1900, and it surmises that he might have been spying in Germany, feeding information to the Scotland Yard superintendent, William Melville.

Other claims in the forthcoming book, some of which were outlined in a recent article in the Sunday Times of London, are that Houdini assisted German police with information about wanted criminals, monitored anarchists in Russia, and engaged in anti-counterfeiting activities for the Secret Service.

“Some of it may be true,” an author and collector of Houdini material, Arthur Moses, said, “but it’s hard to believe it’s all true.” He did say what he has read of the book is meticulously researched and well written.

A call to Mr. Kalush was referred to the publisher’s publicity department, which declined any interviews until closer to the publication date.

“I’ll believe anything that there’s evidence for,” a Houdini biographer who is reserving judgment until he has read the book, Kenneth Silverman, said. But he bristled at the suggestion that Houdini’s quick rise to fame was partly assisted by police. The new book apparently claims that there was a quid pro quo whereby detectives in Chicago would promote Houdini if he taught them lock escapes and other skills. To the contrary, Mr. Silverman maintained, “He owed his huge reputation to the work he did on stage.”

The publisher of Genii magazine, Richard Kaufman, said Mr. Kalush had viewed documents that appear to support the claim that Houdini, if not actually a spy, helped the embryonic British intelligence service gather information.

However, a historian at the Washington-based International Spy Museum, Thomas Boghardt, who has not yet read the book, said British espionage did not start in earnest until 1909. He also said William Melville, the head of Scotland Yard, was principally involved in counterespionage in England rather than spying abroad.

Throughout history, conjurors have engaged in espionage and police and detective work. The French magician Jean Eugène Robert-Houdin (1805-1871) — whose name the young Ehrich Weiss invoked when he renamed himself Harry Houdini — worked as an envoy in Algeria and helped quell an uprising by showing that indigenous Algerian magic could not match French conjuring. During World War II, the illusionist Joseph Dunninger (1892-1975) advised the U.S. Armed Forces on camouflage techniques, the magic scholar Robert Reiss recalled. The sleight-of-hand master John Scarne (1903-1985) also worked for the American Army during the war, showing traveling soldiers how not to be cheated at craps, gambling, and cards.

In the 1950s, the Central Intelligence Agency hired the thaumaturge John Mulholland (1898-1970) to write a pamphlet on sleight of hand to help operatives administer other substances clandestinely — for instance, by slipping drugs into people’s drinks. Defectors during the Cold War were smuggled out of East Germany in cars that were built like the magic boxes used in stage illusions. Magicians have also helped security guards understand how sleight of hand can be used to steal valuable items. More recently, a former acting director of central intelligence, John McLaughlin, has performed magic in demonstrating to intelligence officers how easily they can be fooled even after a magician tells them he is going to fool them.

A professor of security management at John Jay College of Justice, Robert McCrie, said there was a phase between roughly 1915 and the end of the Cold War when celebrities liked to hobnob with spies and international police. He also said that Houdini, as a world-famous magician, had access to this world that most people did not have. But the fact that Houdini might have passed along information to law enforcement did not necessarily make him an operative. “It’s proper to receive credit for trying to be helpful, but the police department can thrive without him.”

One way that Houdini was helpful to law enforcement, Mr. McCrie said, was by showing them that their restraints had limitations and could be overcome.

A historian of American policing and a former Chicago commander of detectives, Thomas Reppetto, said Houdini certainly knew police and had a reason to travel. The claim that he was an agent for police “doesn’t sound impossible. They could certainly have made use of him.”

But to call Houdini a secret agent “in the James Bond sense” might be taking it a little far, a historian of magic, Richard Kohn, said. “He may well have been an observer who passed along observations.” But he also said Houdini was very impressed with himself.

The magician and paranormal debunker James Randi cautioned, “If Houdini had been a spy, that would have gotten out. He never would have been able to sit on it.” Mr. Randi said the story of Jasper Maskelyne (1902-1973) — a magician whose skills at deception helped the British defeat the Germans in North Africa during World War II — got out quickly.

Don Stashower thinks Houdini makes a good private eye – but in fiction. He has written three mystery novels featuring Houdini as a detective. “The same skills that make him a good magician and escape artist,” he said, “also made him an interesting person to cast as a detective because he was naturally good at solving problems and figuring out puzzles.”