It was a gruesome end for the fascist dictator who had once dominated Italy. The corpses of Benito Mussolini and his mistress, Claretta Petacci, were hung upside down on meat hooks in Milan’s Piazzale Loreto. Seventy years ago this month, Mussolini had tried to escape to Switzerland in a convoy of German trucks, but it was intercepted by Italian communist partisans while it was weaving its way along one of the most ravishingly beautiful landscapes in Italy, the western shores of Lake Como.

Just who killed Mussolini remains contentious in Italy, with many theories still unresolved. But there is no disputing that he was executed by machine gun fire while standing against a wall of the Villa Belmonte in a small village near Lake Como, according to most accounts by a communist partisan commander, on the orders of the communist leadership.

Whatever the truth, the death of Il Duce set off instant alarms in the British security services. Somewhere in the Italian archives were copies of correspondence between Winston Churchill and Mussolini. When Churchill became prime minister in May 1940 he tried, in a series of letters, to dissuade Mussolini from joining the Axis powers. He was ignored. Three weeks later Italy joined Nazi Germany and declared war on Great Britain.

Although there would have been copies in London of the Churchill-Mussolini exchanges, none has ever turned up and in April 1945, somebody in London was very anxious that Mussolini’s copies should never see the light of day. The supposition was then—and now—that in his attempts to influence Mussolini, Churchill had offered concessions that by the end of the war would have looked too much like appeasement, although when they were made in 1940 Britain stood desperately alone against Hitler.

In fact, for months the British security services had been conducting a hunt for all of Mussolini’s personal archives as Allied forces swept the German army from its remaining redoubts in northern Italy, where, supported by a local population of hard-line fascists, Mussolini had headed a puppet state named the Salo Republic, named for a small city on Lake Garda.

The Germans had been equally interested in Mussolini’s archives. When he was deposed from power in Rome in 1943 and the city came under German occupation a special unit of the Nazi SS was sent into the Italian Ministry of Affairs in the Palazzo Chigi to seize Mussolini’s papers. Three truckloads were dispatched to Berlin. (Italian officials claimed later that they had already dispersed the most important documents to secret sites in Rome.)

As the war neared its end in 1945 a carefully calculated fog of deception, disinformation, and quintessentially Italian intrigue frustrated the hunt for Mussolini’s surviving papers. As well as the archives, another elusive and exclusive prize was on the checklist—Mussolini’s personal diaries. The dictator was a lifetime insomniac and was believed to have made nightly diary notes that would include, for example, intimate details on his meetings and dealings with Hitler.

Of the diaries, there was no sign. If they existed the Allied intelligence officers believed that, like other documents of the most secret kind, they would have been dispersed and hidden by people who remained loyal Fascists.

This remained the case until, 22 years later, I met a man named Charles Kean.

His very English name notwithstanding, Kean was Polish. (I never got to know his name in Polish.) He was a man of several passports and more than one identity. His English persona seemed to be shaped by archetypes seen in British movies of the ’40s. Some of this was expressed in language from P.G. Wodehouse’s Bertie Wooster novels, in terms like “old chap” that alternated with aphorisms from another self, like “Listen…you put honey on a donkey’s ass, it’s still a donkey’s ass.” He wore Savile Row suits, drove a Jaguar sedan and was a member of a true gentleman’s club, the Reform—like Phineas Fogg.

We first met in Kean’s small flat in Knightsbridge. He hovered uncertainly between wariness and barely controlled excitement. He said he had a business associate in Italy who was in touch with people who claimed to have some of Mussolini’s long-lost diaries. He produced some very poor quality photostats that he claimed were a few pages from the diaries in Mussolini’s own hand.

Why did he come to me? I was in charge of the documentary output of a London TV station. This would not have been a natural home for what might be one of the last great untold stories of World War II. However, a friend of Kean’s had recommended me on the basis that I had been managing editor of the London Sunday Times and run its investigative reporting team.

I asked Kean to loan me the photostats so that I could check the handwriting against existing records. Reluctantly he agreed to let me have them for 24 hours. I went to the library of the Foreign Office where an archivist produced documents with Mussolini’s characteristically large flourishes of penmanship. It was a strikingly good match but based on too little material to be conclusive.

I asked Kean if he realized that there would have to be far more rigorous scrutiny of the actual diaries before they could be accepted as authentic. Kean agreed, but he was in the grip of a fantasy. The diaries would be so explosive that any publisher would have to pay a fortune for them—as much as $12 million. In 1967 dollars that was an eye-watering figure, and I attempted to bring him down to earth. If they were authentic, I said, even $1 million would be a stretch.

It turned out that in Italy there was an extended food chain behind Kean. The next in line was his business associate, Ettore Fumagalli, although it was not clear what their business interests were. They spoke of friends in the Texas oil business; later there were stories about supplying Italian arms to the Suharto regime in Indonesia. Fumagalli claimed that his greatest work was a machine that removed train wrecks from the tracks.

I sent two former members of my Sunday Times investigative reporting team to Milan with Kean, one of them fluent in Italian and with a knowledge of the byzantine politics of Rome. Kean introduced them to the next in the chain, a nephew named Marcello Marconi. He, in turn, explained that the diaries were in the keeping of two women, Guilia and Amalia, who lived in the nearby city of Vercelli.

The women produced diaries for 1940, ’41, and for part of ’43, as well as a transcript of entries from the 1942 diary. In the course of this trip my reporters realized that Fumagalli’s nephew, Marcello, disliked the middlemen and would have preferred to act as the sole intermediary between the women and whoever the buyer turned out to be in London. There was no hope of that happening—Kean ran the show with a tight fist and a vigilant eye.

In any case, my team was persuaded that the diaries were authentic. They had checked out the chronology and details of meetings with the Italian historical records, the physical condition of the diaries looked right, the paper was unusual, said to have been manufactured specially for Mussolini by the state printers, pages were scuffed and the covers were missing “because they were too conspicuous.” The women said that 18 of the diaries were hidden in various locations in Lombardy.

To take the scrutiny of the diaries further needed more resources. Historians with expertise on Mussolini and the period should review every diary page. Paper and ink should be tested for age. Lawyers, Italian and British, would be required to deal with tricky issues like ownership and copyright—it was likely that the Italian government itself had a claim to ownership. There was also the problem of length. If there were diaries for 25 years, as claimed, that would amount to around 1,700,000 words.

My TV company did not have such resources. We agreed that I should take the project to my old boss at the Sunday Times, the editor-in-chief Denis Hamilton. And after reviewing the material, Hamilton agreed to fund continued research in return for exclusive first-world rights to publish, while keeping the whole project confidential until it was time to publish.

I enlisted the help of three historians, including the head of the Italian department at Reading University, who on being told of the discovery waved at a shelf full of works on 20th-century Italy and said, “If these diaries are real, all these books will have to be rewritten.”

“If” would turn out to be a rather important caveat.

Quite early on one of the historians was struck by the apparent chastity of the diaries. He pointed out that for the last decade of Mussolini’s life his emotional pivot had been his mistress, Claretta Petacci. He saw her daily. There were innumerable dramatic and absurd scenes and squabbles, also involving Mussolini’s wife, Rachele. There was no hint of this in the diaries.

“This is particularly interesting,” noted the historian, “because Mussolini was a man of voracious sexual appetite who, as we know from other sources, found it virtually impossible to meet a woman, attractive or otherwise, without trying to rape her on the spot (usually on the floor).”

It seemed to me, though, that the vainglorious Mussolini would hardly bother to include personal details like that when the purpose of his diary was to reflect his role and importance as a major world figure.

As the scrutiny continued Kean grew impatient. It was taking too long. Where was the money? He brought Fumagailli’s nephew Marcello to London to relay the news that the women who controlled the trove were also becoming edgy, worrying for their safety if the Italian authorities got wind of their role and complaining that they did not have enough money to meet their mortgage payments. One of my reporters escorted Marcello around the London sites but his main interest turned out to be buying a large quantity of pornographic photographs in the fleshpots of Soho.

Simultaneously with the scrutiny of the diaries, one of the historians, Martin Gilbert, had on his own gone a long way toward solving the mystery of the Churchill-Mussolini correspondence. (Gilbert, an indefatigable researcher, later became Churchill’s official biographer.) It all hinged on an industrialist and Fascist collaborator named Guido Donegani. Gilbert located a friend of Donegani’s who was with him in the San Vittore prison in Milan in 1945 when Donegani was interrogated by British intelligence.

Gilbert discovered that soon after that interrogation, Donegani was a free man, and was allowed to keep a villa on the Italian Riviera and a lavish apartment in Milan as well as other retreats and a personal fortune.

In August 1945, Churchill, no longer prime minister, having lost a general election, arrived in Milan aboard an American bomber, under the cover name of Colonel Warden. (This was probably the pilot’s name—Colonel Henry Warden was a very well-connected air force pilot.) In Milan his first call was very surprising: He went to a cemetery where Mussolini’s remains were buried under a mound, and stood by it for several minutes, hat in hand.

Churchill had met Mussolini once, briefly, in Rome in 1927. Mussolini was then 44, the youngest leader Italy had ever known, and at the height of his spellbinding powers, widely admired in Europe as a “a man who made the trains run on time.” Churchill was 53, chancellor of the exchequer in London and thought to be beyond his peak (far from it, as things turned out).

After the cemetery visit in Milan, Churchill retired to a villa near the city of Como—a villa owned by none other than Guido Donegani. A mile or so away in a magnificent location on the western shore of Lake Como was Villa d’Este, a classic grand luxe hotel that was then occupied by the British military commander in northern Italy, Field Marshal Alexander. On Alexander’s staff was a Scotsman named Major Malcolm Smith, a senior intelligence officer who had had close contacts with Churchill.

Before Churchill arrived in Milan, Smith had followed the trail taken by Mussolini’s wife Rachele and their children—separate from Mussolini’s own route with his mistress—to a villa in Como. Smith had been tipped off that the Churchill-Mussolini correspondence had probably gone, along with other papers, with the party to Como and had been buried by a secretary in the villa’s garden.

While he was in this welcome Italian idyll Churchill was seen out in public pursuing some of his favorite hobbies—gardening, fishing and painting. There was also a meeting with Alexander—and Donegani. Gilbert, the historian, concluded that the correspondence had been retrieved and handed over to Churchill but it never turned up in the Churchill archives and was never seen again. Donegani died two years later, taking his secrets with him.

My own closest whiff of the Mussolini aura came when I invited his son, Vittorio, to come to London. Contact with Vittorio had been made by Ettore Fumagalli, who had arranged for him to see some of the diaries in Italy. I had two meetings with him in London.

Charles Kean presided at the first meeting and tried to push Vittorio into confirming the authenticity of the diaries, but Vittorio was noncommittal. When I saw him again for a longer meeting without Kean he was more outwardly pessimistic, but it was hard to judge whether this was because Vittorio was sick of living in his father’s shadow or if he really had found the diaries unconvincing.

It was obvious that a crucial, hoped-for endorsement from Mussolini’s son would not be offered. And, at around the same time, things were unraveling in Italy. Fumagalli’s nephew, Marcello Marconi, had met Franco Bandini, a reporter for Domenica del Corriere, a weekly newsmagazine. He told Bandini that the British were in the process of buying the Mussolini diaries, that a contract had been signed, but that the “half-witted English could be double-crossed” and, instead, the diaries could still be had—for a sizeable sum—by Domenica del Corriere.

Just who had conceived the attempted double-cross never emerged. In London, Kean had been demanding increasingly large down payments in order, he said, to forestall competitive bids from both Europe and the U.S.

Kean then used a classic gambit of the con man with nerves of steel. He deflected attention away from a deeply suspicious detail by actually revealing it. He asked all the parties involved in London to sign a document saying that we would never, under any circumstances, reveal the name of the town Vercelli or the names of the two women.

Why? Because a decade or so earlier they had been falsely accused of trying to sell fake transcripts of Mussolini’s speeches to a Milan magazine—a case brought, he claimed, as a result of an anti-Fascist campaign designed to expunge all records of Il Duce’s words and thoughts. They had, Kean said, gone to prison, and lived in fear of going through that ordeal again.

But Marconi’s astonishing offer to the Italian reporter had backfired. Bandini found in his own magazine’s archives the record of the earlier charges against Guilia and Amalia in which their ability to replicate Mussolini’s handwriting was conceded to have been uncanny. Nonetheless, they had re-emerged and embarked upon this far grander scheme, the composition of 25 years of Mussolini’s diaries. Somehow they had found expert technical accomplices. The ink and paper had passed “scientific” tests in London.

Astonishingly, nearly a year of expert scrutiny had not exposed their fraud. The investigation, hefty legal fees in both London and Italy and advances made to Kean had cost the owner of the Sunday Times, Lord Thomson, about $1 million in today’s dollars. Fortunately not a word had been published before the scam was exposed. Thomson took a philosophical view. A number of seasoned, hard-nosed journalists (including me) had succumbed, he said, to “scoop angst”—they were so anxious to keep the story under wraps for fear of having it snatched from them that they had not practiced due diligence as required. I had no argument with that, and since then I have always thought that the trickiest part of journalism is to strike the right balance between skepticism and credulity—if you’re too skeptical you can sometimes reject a story that turns out to be true, no matter how far-fetched, and if you’re too credulous you end up with Mussolini’s diaries.

But the plot was not quite done. Five years later one of the reporters I assigned to the case, by then a senior television executive, had a visit from two Interpol detectives, one British and one Italian. Guilia and Amalia had never gone to prison, they said. Not for the first forgeries, and not for the diaries. Guilia had since died but Amalia was still in Vercelli and, for some reason, the Italian examining magistrate in Vercelli had re-opened the case, wanting to prosecute Amalia for forging “state documents.”

But, amazingly, both Interpol detectives set out their doubts that the documents had been forged at all. There had never been any direct evidence that they were. There was, for example, the expert testimony on the age of the paper and the ink. Moreover, the Italian Interpol agent, a Doctor Delfino, said there were certain people in Italy who needed people to believe that the diaries were forged because, if they were authentic, they would encourage a revival of the Mussolini cult and Fascism.

In a note to me about this interview my old colleague said: “I always felt the diaries could be genuine. They looked absolutely right and it would have required an amazing effort to have concocted them. And the ladies never looked like forgers to me.”

A couple of years after I received that note I was with my family in a line at passport control on the island of Majorca, leaving after a holiday. Suddenly I noticed in an adjacent line somebody submitting for examination an extra-thick passport, the kind used by people who burn through passports at a high rate. It was Charles Kean. I named out to him. He gave me a quick glance and made a rapid exit toward his airplane. By the time our own passports were stamped he had disappeared.

Epilogue: In 1983 the London Sunday Times, together with the German newsweekly Stern, announced that they had found the “secret” diaries of Adolf Hitler. Stern said that the diaries had been scrutinized for 18 months by experts. On examining the diaries, Britain’s leading historian on Hitler, Lord Dacre, said, “I am now satisfied that the diaries are authentic.” Rupert Murdoch then owned the London Sunday Times. As the first extract from the diaries was about to be published, Dacre suddenly expressed doubts and said they should have more scrutiny, but Murdoch went ahead and published anyway. Shortly afterward they were proved to be fakes. The editors of Stern and the Sunday Times resigned.