(see related story) (ANSA) - Milan, October 10 - The arrest of Lombardy executive regional councillor Domenico Zambetti shows organized crime gangs are capable of violating democracy, Milan prosecutor Ilda Boccassini said Wednesday. Zambetti, a member of ex-premier Silvio Berlusconi's People of Freedom (PdL) party, is accused of paying 'Ndrangheta mobsters 200,000 euros for 4,000 votes (at 50 euros each) in the 2010 elections for the assembly of the region around Italy's business capital Milan. Boccassini said the investigation, which led to 20 arrests on Wednesday including Zambetti's, had showed 'Ndrangheta's ability to affect "the democracy of the country and the freedom to vote". She said the probe had also uncovered evidence that the powerful syndicate, which is originally from the southern region of Calabria but has spread to wealthier northern regions in recent years, contaminated the vote for Milan's city council last year. Boccassini said Zambetti became an "asset for the mafia organization and it demanded favours from him". An alleged example of this was the fact that Zambetti had the daughter of an alleged Ndrangheta' boss, Eugenio Costantino, hired by a regional agency. Lombardy Governor Roberto Formigoni said via Twitter that he had relieved Zambetti of his duties because of the gravity of the allegations. Milan Mayor Giuliano Pisapia said Formigoni, who is being probed as part of a corruption investigation into health-sector contracts, should quit in the light of Zambetti's arrest. "After this latest development, it's not possible to go on like this," Pisapia said.