MILAN, Jan 29 (Reuters) - Italian tax police have seized 46.6 million euros ($48.4 million) from FedEx's FDX.N local unit, FedEx Express Italy srl, following an investigation into alleged tax fraud linked to illicit labour supply, prosecutors' documents showed on Wednesday.

In a 75-page decree reviewed by Reuters, Milan prosecutors accused the U.S. package delivery giant's local unit of circumventing labour and tax laws, relying on cooperatives or limited liability companies that supplied workers while omitting tax and social security payments.

FedEx did not immediately respond to requests for comment from Reuters.

Prosecutors said in their decree that FedEx Express Italy, sometimes using intermediaries acting as filters, used "bogus procurement contracts for the provision of services" with these cooperatives or companies that were a front for cheap labour, and made false tax declarations.

Prosecutors denounced it as a "fraudulent" business model that "facilitates the exploitation of workers and results in unfair competition", adding that it has been common malpractice in Italy for years, if not decades.

Similar investigations into irregular hiring schemes have targeted other large businesses in recent years including global delivery groups DHL and GLS, U.S. logistic giant GXO Logistics GXO.N, German logistics firm DB Schenker and Italian supermarket chain Esselunga, Milan prosecutors said.

In their decree, Milan prosecutors listed 19 large companies at the centre of similar investigations in recent years and said all these businesses have so far paid more than 552 million euros to the Italian tax authorities to bring themselves into compliance.

"In addition, the companies in question proceeded to internalize employees, previously 'at the mercy' of the reservoirs of cheap labour", prosecutors said in the document.

($1 = 0.9627 euros)

(Reporting by Emilio Parodi, editing by)

((emilio.parodi@thomsonreuters.com; +39 06 8030 7744))