Japan’s Fair Trade Commission has conducted a raid on Amazon over antitrust concerns. “There is a suspicion that Amazon Japan is forcing sellers to cut prices in an irrational way.”

Amazon Japan received an on-site inspection by the regulator today to explore whether the retailer gives better product placement in search results to sellers who offer lower prices. Additional reporting in The Japan Times suggested that this inquiry is focused on Amazon’s Buy Box program, which puts recommended items more prominently in front of online shoppers. The publication said that in addition to demanding “competitive pricing,” sellers were allegedly required to use Amazon’s in-house services, such as those for logistics and payment collection, to qualify for Buy Box placement.

The Japanese FTC has not released an official statement about the inquiry. Amazon Japan’s comment to Engadget on the situation states, “We are cooperating fully with the authorities.”

Amazon has also been questioned about anti-competitive behavior around the world. Stateside, both the Fair Trade Commission and the Attorney General of Washington DC have raised similar concerns about Amazon’s practices. The company is also expected to face an antitrust investigation in the European Union next year.