MILAN, Dec 17 (Reuters) - Italy's tax police on Tuesday

searched the headquarters of nine courier companies for alleged

false invoices benefiting ecommerce and logistics giants Amazon ( AMZN )

, SDA and GLS, a search order reviewed by Reuters said.

Prosecutors in the northwestern city of Turin are

investigating Amazon Italia Transport and Amazon City Logistica,

Italian units of Amazon ( AMZN ), SDA Express Courier and General

Logistics System Enterprise (GLS) for alleged tax fraud and

illegal labour practices, according to the 23-page order.

SDA is part of Poste Italiane group, while GLS is a

subsidiary of British group International Distribution Services

.

Poste declined to comment. Amazon ( AMZN ) had no immediate comment

when reached by Reuters. GLS did not reply to an e-mailed

request for comment from Reuters.

($1 = 0.9521 euros)