Urbano Lazzaro, a resistance fighter credited with arresting fascist dictator Benito Mussolini at the end of World War II, has died at age 81, officials said Wednesday.

Lazzaro died Tuesday after being hospitalized in Vercelli, a town between Milan and Turin, officials at St. Andrea hospital said, refusing to be identified further because they were not authorized to give the information.

Lazzaro, known to his comrades as "Partisan Bill," fought with a communist resistance group in northern Italy and is known as the man who captured Mussolini in the dying days of the war, Italy's National Partisan Association said.

In April 1945, with Nazi forces in full retreat and Italians rising up against the fascist puppet state of Salo, Mussolini fled north in a German convoy.

Lazzaro was among a group of resistance fighters who stopped the retreating convoy near Dongo, on the shores of Lake Como. On the lookout for fleeing fascists, the partisans searched the trucks and Lazzaro recognized "Il Duce" disguised as a German soldier.

Mussolini and his mistress, Claretta Petacci, were executed after a summary trial, although the details of the dictator's demise are often a matter of debate in Italy.

Lazzaro eventually wrote books on those final hours, challenging the official story by claiming that Mussolini was killed by mistake during an escape attempt, news reports have said.

After the war, Lazzaro married and had three daughters who survive him, the ANSA news agency said. He divided his time between San Germano, near Vercelli, and Rio de Janeiro, Brazil.

A funeral will be held Thursday in San Germano, ANSA said.