The Department of Justice (DOJ) may be preparing to file an antitrust lawsuit against Google over its advertising business.

Google has faced ongoing scrutiny over its advertising business, thanks to its dominance in the search market. According to Bloomberg, the DOJ could be ready to move forward with its case as soon as September.

Google controls the entire advertising stack, from the tools websites use to the search engines customers use to find websites. Given the company’s dominance in the search industry, the DOJ believes it represents an illegal monopoly.

This isn’t the first time Google has faced issues as a result of its dominance. Senators recently introduced a bill to force Google and Meta to divest all or parts of their advertising businesses as a result of their tight control over the entire process.

Google denies any wrongdoing.

“Our advertising technologies help websites and apps fund their content, and enable small businesses to reach customers around the world,” said Google spokesperson Peter Schottenfels. “The enormous competition in online advertising has made online ads more relevant, reduced ad tech fees, and expanded options for publishers and advertisers.”