One ill-fated night in December 1924, F. Scott Fitzgerald got into a drunken brawl that ended up in a Rome police station, where he punched an officer and was severely beaten by some others.

In a letter to a friend ten years later, Fitzgerald described it as “the rottenest thing that ever happened in my life,” an event so traumatic that his biographers say he could not bear to discuss it. But Fitzgerald fictionalized the incident twice, initially in a travelogue called “The High Cost of Macaroni,” written in 1925 but published posthumously, and more famously in his 1934 novel “Tender is the Night.”

In the novel, a very intoxicated Dick Diver, the protagonist, has a vicious scuffle in Rome with some taxi drivers, gets arrested and, after hitting an officer at a police station, is “clubbed down, and fists and boots beat on him in a savage tattoo.” He ends up arrested, bloody and broken, only to be salvaged by his sister-in-law and officials from the U.S. Consulate. In Fitzgerald’s case, his wife Zelda came to the rescue.

Biographers of Fitzgerald have taken the writer’s fictitious accounts as fact. But official reports by Italian police and diplomats from the consulate in Rome, uncovered by Sara Antonelli, a professor of American literature at the Università Roma Tre, suggest that doing so can obscure the full truth.

“I had this buzzing thing in my head for years,” she said. “The fact that in all the biographies they kept saying that what you read in ‘Tender’ happened to Fitzgerald. But I’m a literary critic — this is not the way things work.”

Antonelli’s quest for clarity took more than three years and many hours mining the historical archives of Italy’s various police forces. At Rome’s central state archive, she uncovered a single pink folder labeled “Arrest of the Foreigner Scott Fitgerat” with five sheets of paper inside: an initial report by the carabinieri, the military police force that detained and beat up Fitzgerald on the night between Nov. 30 and Dec. 1, 1924, along with follow-up reports by the Italian national police, the country’s civilian force.