Following similar investigations into Google and Apple, tax police reportedly handed Milan prosecutors a dossier on their investigations on 2009 to 2014 returns by the world's largest online retailer.
The prosecution service did not immediately confirm the report.
The development comes amid fierce controversy over the complex tax arrangements of multinational corporations under fire in Europe for slashing their tax bills by shifting revenue across borders. Investigators estimate Amazon funnelled its fiscal returns through Luxembourg's ultra low tax regime to slash its tax bill on around 2.5 billion euros of Italian receipts.
In a statement, Amazon denied the claim, adding it had invested some 800 million euros over the past seven years in Italy, where it employs about 2,000 people, and had reduced profits there to ramp down its tax exposure.
Amazon on Thursday delivered stronger-than-expected financial results for the first quarter, pushing shares higher on profits up 41 percent from a year ago to $724 million on revenues growing 23 percent to $35.7 billion.
Italy in December 2015 reached agreement with another US tech giant, Apple, for 318 millions euros to settle a tax dispute going back to 2008. Rome is also chasing after Google for 227 millions euros in back taxes on Italian revenue declared in Ireland, whose tax regime is more favourable to the tech stalwart.
Italy is also making tax demands from Facebook, according to Italian media.
Copyright Agence France-Presse, 2017