Google may soon have another lawsuit on its hands. The Federal Trade Commission is about to launch an investigation into whether Google unfairly used Android’s strength in the mobile computing market to prioritize its own services over those of competitors, Bloomberg reported, citing two anonymous sources.

This may seem counterintuitive at first. After all, Android is open source, and Google gives it away for free to carriers. The catch is that Google’s own apps, such as the Play store, Gmail, YouTube and Google Maps, aren’t open source. And, as we’ve explained previously, if a manufacturer or carrier wants to ship an Android phone with those apps, they need Google’s permission. That means that, in theory, Google can stop a carrier from promoting its own services that compete with Google’s by withholding permission to use key apps.

As Bloomberg notes, the investigation could wind up without Google ever being accused of wrongdoing. After all, the FTC declined to file charges against the company in 2013 after a wide-ranging investigation into its business practices.

Google did not immediately respond to a request for comment.

The question for regulators is whether this bundling constitutes anticompetitive behavior, given Android’s strength in the market. The FTC will have to decide whether Android’s 59 percent share of the US mobile operating system market counts as a monopoly.

Meanwhile, the European Union is moving forward with its own antitrust case against Google, which, in addition to questing Google’s Android practices, alleges that the company stifled competition in the online shopping market.