Sicilian judge Antonino Di Matteo is one of the most threatened - and protected - men in Italy. As the chief prosecutor in Italy's "trial of the century", he has more than 20 bodyguards, ensuring his safety around the clock. On trial are 10 men who stand accused of being part of a conspiracy between the mafia and the state. Five of the defendants are mafia bosses and five are members of the political establishment, including senior police chiefs and politicians. Central to Di Matteo's case is the story of Italy's most famous anti-mafia judges, Giovanni Falcone and Paolo Borsellino. During the 1980s they prosecuted hundreds of Cosa Nostra members in what was known as the Maxi Trial, the largest mafia court case in history. Four-hundred-and-seventy-five mafiosi were brought to court and 346 were found guilty. "For over 130 years in Italy we pretended the mafia didn't exist. Not until Giovanni Falcone and Paolo Borsellino did we have magistrates in Sicily who said, 'No. The mafia in Italy exists. The mafia in Sicily exists. And it's the judiciary's duty to fight and try to destroy the mafia'," says Saverio Lodato, author of Forty Years of Mafia. The Cosa Nostra "boss of bosses", Salvatore "Toto" Riina, had been tried in absentia and sentenced to life in prison. After the trial, Riina allegedly sought revenge. Judge Giovanni Falcone was assassinated on May 23, 1992 near the mafia heartland of Palermo. Two months later, while investigating Falcone's murder, Judge Paolo Borsellino was also killed by a massive car bomb in Via D'Amelio, a residential street in Palermo. Inspired by these two judges, Di Matteo is now taking up where they left off. He is trying to shine a light on Italy's so-called season of terror from 1991 to 1994, when the mafia organised a series of bombings and murders to force a negotiation with the government. "I was brought up with the legend of Giovanni Falcone and Paolo Borsellino. I was a law student when they were working on the Maxi Trial. In those men ... I saw a chance to fight back," Di Matteo says. He has received a series of death threats. In an attempt to halt the trial, Riina, who is now behind bars, called for Di Matteo's assassination. He was caught on a prison CCTV camera telling a fellow prisoner: "So if we can, kill him. It'll be an execution like we used to have in Palermo." Many Italians have taken to the streets in solidarity with the judge. But there has been a notable silence from political leaders. "We citizens are angry. The more we realise that no one is interested in Dr Di Matteo, the angrier we become," says Linda Grasso, the founder of Civilian Bodyguards, a movement to protect the prosecutor. "I want to know the reason for this silence. What are they frightened of? Why are they silent? We can't allow this man, a hero to us, to suffer this silence and indifference from the institutions.... We want to protect our judges while they're alive, not commemorate them after their deaths." The threat to Di Matteo hasn't prevented the magistrate from attending the courtroom. The trial is ongoing and all of the accused deny the charges against them. "I am conflicted. To give up would be a personal defeat. But it would offer respite for me and my family. Finally, a margin of freedom. Maybe even tranquillity. But only maybe. Even if I gave up, it doesn't mean I would get fewer death threats," Di Matteo reflects. "We knew from the beginning that it would be an uphill struggle. A road littered with attacks, pitfalls, moments of difficulty. "I believe the truth about these massacres, which have made all decent Italians weep, can be found in the stories we are trying to open up. If we don't uncover our history we can't progress. We run the risk that this disease of the past that still plagues us today could infect our future." A Very Sicilian Justice, narrated by Helen Mirren, is an intimate portrait of an Italian judge living under constant threat as he tries to take on the mafia. Among those profiled in the film are a former mafia assassin-turned-state witness as well as Borsellino's brother, and the son of late former mayor of Palermo Vito Ciancimino, who was also known as "Don Vito".