According to CP World, 17 properties were seized and 20 arrest warrants were executed during the operation.
Local reports suggest the seizes took place following the results of an investigation regarding unusual activities between an Irish developer, two Spanish investors and the ’Ndrangheta, the Calabrian Mafia.
"This scam is the result of the combination between massive influx of outside capital and, above all, the ability of criminal organizations to govern and 'control' the territory, thus guaranteeing the purchase of land and the development of projects," Massimo Minniti, preliminary investigative judge in the case, said in a statement.
The Irish developer, identified as Harry Fitzsimmons, was not arrested because he lives in a country that does not recognize Italian warrants, the Irish Times noted.
The group's illicit activities are not exclusive to Italy. Police reportedly seized over $600 million in assets in Britain and Spain.
Veteran mafia investigator Nicola Gratti called the operation “the most important investigation into money laundering in Italy in the last 10 years”.