Italy’s antitrust authority said it’s investigating Apple Inc. and Amazon.com Inc. after a local retailer complained they’d been banned from re-selling products on the online marketplace.

The Italian offices of both companies were inspected Wednesday by authorities, according to a statement Wednesday. Apple and Amazon are suspected of unfairly curbing the sale of the iPhone maker’s Beats products by anyone other than members of its official reseller program.

This could “lower the incentives for efficient competition on the prices of Apple and Beats products” with “negative effects for consumers and businesses,” the authority said in a statement.

A representative for Apple didn’t immediately respond to requests for comment. A spokesman for Amazon said the company is “fully collaborating with the authority.”

The Italian probe comes as both companies are facing in-depth scrutiny from the European Union’s antitrust authority in areas central to their business. The EU in June opened multiple antitrust probes into Apple’s (AAPL) conduct, including rules requiring that app developers use its App Store payment service.

Meanwhile, Amazon (AMZN) is said to face a formal antitrust complaint in the coming weeks from EU regulators amid concerns the U.S. retail giant may be shortchanging smaller merchants who sell on its marketplace.

In its statement, the Italian authority said it was told many retailers had been removed from Amazon’s local marketplace as a result of re-selling Apple products without being an ordained vendor. It said the retailers believed they were operating legitimately. It didn’t say how many businesses were understood to be affected.