Police believe Manno had been storing the money for a top Mafia boss
Italian police say they have seized $10m (7.1m euros; £6.3m) in fake money and a large arms cache from the houses of a Mafia boss and his relative.
Most of the "currency" was found at the Sicily home of Fabio Manno, one of more than 100 people arrested in a major anti-mafia operation in December.
More money, in $100 bills, and weapons were discovered inside a wall at the home of Manno's aunt on the island.
The notes were said to be of "excellent quality" and had been produced locally.
Police said they believed Manno had been storing the money and weapons for Gaetano Lo Presti, a top boss in the Sicilian Mafia - also known as the Cosa Nostra - who hanged himself in his cell hours after he was arrested in December's operation.
Lo Presti had been vying for overall leadership of the Cosa Nostra and had planned to use them to eliminate opponents and finance his rise to the top, the police added.
Officials say the Cosa Nostra has been severely weakened by a series of major arrests in recent years, including that of its last known "Boss of Bosses", Bernardo Provenzano, in 2006.
Provenzano is believed to have handed the reins to Salvatore Lo Piccolo, who was arrested in November 2007.