A bible used by jailed Mafia superboss Bernardo Provenzano has been sent to the United States to see if the Federal Bureau of Investigation can find codes the boss may have used to send messages .
Italian police experts have tried in vain to make sense of the boss's scribbles on post-it notes he stuck into the well-thumbed bible and the typescripts he copied out of it .
Now they've decided to send it to the FBI's Cryptanalysis and Racketeering Records Unit, one of the world's top code-breaking teams .
Italy's Anti-Mafia chief Piero Grasso stressed the importance of doing "everything possible" to see if the bible had a secret use .
Investigators suspect the bible may contain ciphers used to encrypt the notes the 73-year-old Don used to communicate with bosses around Sicily .
Provenzano may have sent similarly annotated copies of the holy book to his Cosa Nostra brothers so they could use them to decode the notes, Italian police think .
He may even have had such copies sent to powerful bosses in prison. The Bible is one of the few books allowed to mafiosi serving time under Italy's toughest prison regime .
Police have already deciphered many of the notes found in the boss's hideout and discovered a number system used to identify bosses and order crimes .
Their work has led to a string of arrests .
But the bible comments and copied biblical passages have proved harder to crack .
Despite investigators' optimism, Grasso indicated that the bible may not prove to be the key to the remaining notes. "It's a hunch that has to be proven," he said .
Provenzano had five bibles with him when he was caught on April 11 after 43 years in hiding .
The annotated copy was by his bedside .
It was the first thing he asked for when he was moved to solitary confinement shortly after his arrest .
His request was turned down. He was given a prison bible, which is currently his only reading matter .
One of the boss's favourite biblical parts, according to what he was found to have copied out, was the Book of the Apocalypse .
He typed out whole chunks complete with notes on the exact meaning of words like "vice" and "fornicate" .
One passage reads: "The beast you saw was there but is already gone: it is about to rise out of the abyss and go to its ruin". Like several Cosa Nostra dons, Provenzano is said to have been a devoted Catholic, in his own way .
Police found religious trappings including cheap posters of the friar with the stigmata, San (Padre) Pio, in the tumbledown farmhouse in which Provenzano spent his last years .
Provenzano is believed to have had a close support network in Corleone, the town 40km (25 miles) south of Palermo made famous by the Godfather films .
Investigators also suspect he enjoyed protection from local politicians and rogue police officers .
The boss, who took sole command of Cosa Nostra when co-boss Toto' 'the Beast' Riina was arrested 13 years ago, is being held in a single cell in a high-security prison in Terni, central Italy .
He has so far made four appearances via video-link at a trial for crimes committed in the 1980s .
Provenzano has been convicted in absentia of a string of murders he committed as a young hitman and more recent assassinations he approved including the 1992 bomb slayings of Italy's top anti-Mafia judges Giovanni Falcone and Paolo Borsellino .
