(By Denis Greenan). Palermo, April 3 - Italian police on Wednesday made the biggest-ever assets seizure in the history of the country as they hit a Sicilian wind-farm mogul linked to the fugitive head of the Sicilian Mafia. In a dawn raid across Italy, anti-Mafia police seized assets worth over 1.3 billion euros belonging to Sicilian wind-farm and solar-power magnate Vito Nicastri. The National Anti-Mafia Directorate (DIA) said Nicastri was linked to Cosa Nostra's reputed head, Matteo Messina Denaro. The operation involved 43 companies or stakes in companies, 98 properties, seven vehicles and 66 financial assets, including bank accounts, credit cards and life-insurance policies, belonging to Nicastri, a leading player in the clean-energy sector. "We have hit the heart of the grey area of Cosa Nostra," investigators said. As well as Sicily, assets were seized in Lombardy, Lazio and Calabria. Investigators said the 57-year-old businessman from Alcamo, in western Sicily, "maintained constant relations with members of Cosa Nostra" in the provinces of Catania, Messina and Palermo, as well as having contacts with Calabrian crime syndicate 'Ndrangheta. This relationship allegedly "facilitated his transformation from an electrician into a businessman specialising in the production of electricity from renewable sources, giving him a prominent position in the south (of Italy)". In a "tumultuous business dynamic," they added, Nicastri had "relations" with companies in Luxembourg, Denmark and Spain. The businessman, who was put under "special supervision" in which he will have to regularly sign in at police stations, has been involved in previous probes which revealed Cosa Nostra's "huge" involvement in wind farms near Trapani, Messina Denaro's home turf, investigators said. The record assets seizure is the latest in the anti-Mafia prosecutors' 'scorched earth' policy aimed at draining Messina Denaro's resources and exposing him, police said. Despite his life as a fugitive, Messina Denaro is still reportedly active as the closest thing the Mafia has to a chief following the capture of Bernardo Provenzano in 2006 after 43 years on the run. On Tuesday the Il Fatto Quotidiano daily reported that Messina Denaro was planning to kill a prosecutor leading a case against police allegedly involved in suspected secret 1990s talks with the State to stop a bombing campaign that claimed the lives of magistrates Giovanni Falcone and Paolo Borsellino. Details of Messina Denaro's alleged assassination plan against Palermo prosecutor Nino Di Matteo were contained in two anonymous letters sent to Palermo prosecutors a few days ago, the daily said. The government immediately ordered Di Matteo's police protection to be beefed up. The report was the first claim that Messina Denaro was planning to kill a prosecutor. It came as a surprise in the light of the Italian police's repeated reports they have severely dented the Mafia chief's power by arresting associates and seizing assets. In the last seizure before Wednesday's, on January 25, hundreds of thousands of euros in olive-oil businesses, cars and bank accounts were confiscated or frozen. They were in the name of Messina Denaro's sister Anna and her husband, detained on Mafia charges, 43-year-old Vincenzo Panicola. A wave of arrests over recent years have closed the net around the 50-year-old Messina Denaro, one of the world's 10 most-wanted men, according to Interpol. In 2011 the hunt kicked into a new gear when police issued a new identikit picture of him. A year previously they were able to reconstruct his DNA. Messina Denaro built up his power base in his native Trapani, in western Sicily, before beating Palermo chieftains to become Mob kingpin after 'boss of bosses' Provenzano was caught in April 2006. His position at the top of Cosa Nostra was assured with the November 2007 arrest of Palermo boss Salvatore Lo Piccolo, a veteran mafia chieftain who had appeared to be vying with the younger mobster for control of crime syndicate and had the apparent support of the 'old guard'. Messina Denaro had been expanding his criminal empire abroad and police found evidence of trips to Austria, Greece, Spain and Tunisia. But police launched a major counter-offensive, implementing their 'scorched earth' campaign to try and flush Messina Denaro out, arresting scores of his underlings and seizing million of euros in assets. "The circle is closing around the No.1 fugitive," then interior minister Roberto Maroni said in 2010. Palermo Chief Prosecutor Francesco Messineo added at the time that their aim of the strategy against Messina Denaro was to "dry up the water he swims in". Last May then National Anti-Mafia Prosecutor Pietro Grasso, who has since become Senate Speaker after being elected for the centre-left Democratic Party in February elections, said the efforts had been so successful that "the Mafia effectively no longer has a No.1". Nicknamed 'Diabolik' after a cult Italian comic strip criminal, Messina Denaro sealed a reputation for brutality by murdering a rival Trapani boss and strangling his three-months pregnant girlfriend. He is reportedly idolised by Cosa Nostra younger troops because of his ruthlessness and playboy-like charisma.