Prison authorities have tightened the screw on Mafia kingpin Bernardo Provenzano to stop him pulling the strings of his Cosa Nostra empire from inside his cell.
Probes have shown that the long-time 'boss of bosses' ''is persisting in lamentable conduct which appear in perfect continuity with a Mafia leadership role,'' prison authorities said Friday.
Since his arrest in April 2006 outside Corleone, Provenzano has been in isolation - first at Terni in Umbria and now at Novara in Piedmont - and his contact with the outside is strictly limited and closely monitored.
Even when he leaves his cell for daily exercise he is under constant surveillance.
But recent probes have uncovered that the 75-year-old boss still has ''worrying'' links to his former world, authorities said.
A series of letters from Mob figures and a parcel with an unspecified content have had to be blocked, they said.
Provenzano is still communicating via coded messages, ''impudently'' using the prison Bible he asked for as a devout Catholic and was given ''out of respect for basic human rights''.
During his 43 years on the run, the Mafia leader shunned all methods of communication other than coded messages, many of them encrypted with a still-mysterious system of Biblical references.
The non-Biblical notes have been decoded but the others have proven harder to crack.
The FBI's codebreakers have been called in to help.
As a result of recent investigations, jail authorities said, ''all communication'' with outsiders will now be cut off.
The authorities said they were partly acting because of the ''harmful'' effect on warder morale and the atmosphere in the jail caused by the impression that the Cosa Nostra supremo was able to continue his rule from the inside.
After his arrest, the Corleone Don was believed to have handed the reins of Cosa Nostra to a younger man, Salvatore Lo Piccolo.
Lo Piccolo was arrested last November and police are not yet sure where the official mantle of 'boss of bosses' now lies.
