Rome, Nov 7 : Italian police seized over 10 million euros ($10.7 million) from 11 companies for alleged tax fraud in connection with a probe into mafia infiltration of contracting works awarded by the country's railway operator, authorities said. The operation was coordinated by the Anti-Mafia District Directorate (DDA) in Milan, reports Xinhua news agency. It follows a previous probe that in early 2022 led to the arrest of 15 people charged with tax fraud, bankruptcy, money laundering and mafia association. All but one of them were later convicted in court. Italy's railway operator RFI is a defendant in the investigation. The 11 companies under probe provided maintenance, vehicles and staff to various RFI stations across the country for years, the previous investigation ascertained. Authorities believed they were all fictitious and connected to a "group of people closely linked to the 'Ndrangheta gang called Nicoscia-Arena" based near Crotone in the southern Calabria region. The new inquiry allowed finance police to piece together "the million-worth circuit of false invoices issued to cover contracts for the supply of specialised labour and vehicle (to RFI) in order to circumvent the anti-mafia legislation and the limitations to subcontracting public contracts", the Guardia di Finanza (GdF, financial police) said. 'Ndrangheta is one of Italy's three traditional mafia organizations, and is now seen as the richest and most dangerous one. Originated in the Calabria region, it has grown into a worldwide operating criminal organization, and is present across Italy and Europe. According to a recent assessment by the European Union Agency for Law Enforcement Cooperation, it is responsible for "much of Europe's cocaine trade, combined with systematic money laundering, bribery and violence". /IANS