- 'An absolute monarchy' -

"It's infinitely less powerful than before. After the deaths of (boss Bernardo) Provenzano and Riina, the only one at liberty is being hunted by the police," the head of Italy's national anti-mafia body, Maurizio De Lucia, told AFP.

Multi-murderer playboy Messina Denaro, one of the world's most-wanted men, is seen by many as Riina's natural heir but has been on the run since 1993.

"Cosa Nostra is a very strictly structured organisation, similar to an absolute monarchy. While the king still lives, it's not possible to think of picking a successor," De Lucia said.

"The question now is whether the organisation is strong enough to identify and appoint an heir. Many of its bosses have been arrested, and enormous amounts of its patrimony has been seized" over the years, he said.