Sicilian police said on Tuesday they had seized 700 million euros ($884 million) of assets from an entrepreneur accused of being "banker" to a fugitive Mafia boss, demonstrating the scale of the Cosa Nostra's business interests.

Anti-mafia prosecutor Roberto Scarpinato told reporters in Palermo that the seizure of property and businesses from Sicilian "supermarket king" Giuseppe Grigoli was "one of the biggest anti-Mafia operations in recent years".

Grigoli was arrested last year for alleged links to Matteo Messina Denaro, one of the most powerful godfathers at large since the arrest of "boss of bosses" Bernardo Provenzano in 2006 and his heir apparent Salvatore Lo Piccolo in 2007.

Senator Costantino Garraffa, from parliament's anti-Mafia committee, welcomed the asset seizure, saying: "Confiscating Mafia property isolates it economically and demonstrates how much its activities damage the legal economy."

Scarpinato, assistant prosecutor in the island capital, said Grigoli dominated the supermarket distribution networks in the west of Sicily, allowing him to employ "hundreds of people close to the Cosa Nostra or recommended by the Mafia".

The prosecutor told a news conference that, from evidence discovered on tiny "pizzini" or paper-scrap messages found in the hut where Provenzano was arrested, Messina Denaro "knew to the last comma the accounts of Grigoli's supermarkets".

Anti-Mafia magistrates in Sicily and elsewhere in southern Italy have said crime organisations have been using discount chains and supermarkets to launder money.