There is no established explanation for how the account of Palatucci’s heroics took hold, but some experts say its persistence owed much to the flattering light it shed on Italy after the war. Scholars said the new evidence surfaced in recent years as they gained access to documents. The goal of their research, they said, was to understand the role of Fiume, the city where Palatucci worked, as a breeding ground for fascism; the documents that undermined the account of Palatucci’s selfless heroism were a byproduct of that investigation.

Palatucci has been credited with saving thousands of Jews between 1940 and 1944 while he was police chief in Fiume, an Adriatic port city that was considered the first symbol of Italy’s new Fascist Empire. (It is now called Rijeka and is part of Croatia.) When the Nazis occupied the city in 1943, for example, Palatucci was said to have destroyed records to prevent the Germans from sending Fiume’s Jews to concentration camps. His own death at age 35 in a camp at Dachau seemed to corroborate his valor.

But Natalia Indrimi, the executive director of the Centro Primo Levi, said historians have been able to review these supposedly destroyed records in the Rijeka State Archives.

What they show, said Dr. Indrimi, who coordinated the research, is that Fiume had only 500 Jews by 1943, and that most of them — 412, or about 80 percent — ended up at Auschwitz, a higher percentage than in any other Italian city. The research on Palatucci found that rather than being police chief, he was the adjunct deputy commissary responsible for enforcing Fascist Italy’s racial laws. What’s more, his deportation to Dachau in 1944 was not related to saving Jews but to German accusations of embezzlement and treason for passing plans for the postwar independence of Fiume to the British.

The report said it was possible that Palatucci had helped a handful of people, although it was unclear whether he had done this on the orders of superiors.