Amazon's much-hyped Prime Day has now been clouded by more than just striking workers, as new reports indicate the European Union is setting its sights on the retail giant.

Bloomberg reported Tuesday that E.U. competition commissioner Margrethe Vestige—who has sued so many tech companies that President Donald Trump accused her of “hating the United States”—is now putting Amazon in the crosshairs for their practices related to third-party sellers. A formal, “full-blown” antitrust investigation into the company is likely to start “within days,” sources reported.

The impending E.U. investigation is likely to focus on how Amazon uses data from third-party sellers, as the company has been criticized for allegedly using data from third-party sellers who use the retail platform to create their own similar, competing merchandise through the company's AmazonBasics brand.