The Justice Department is preparing an antitrust investigation into tech giant Google, reports the Wall Street Journal.

Why it matters: A DOJ investigation would represent an increase in regulatory scrutiny on Google in the United States at a time when the president has attacked the company by name.

Details: According to WSJ sources, the DOJ plans to analyze Google's business practices and how it designs and runs its services, though the precise focus of the investigation remains unknown.

A spokesperson for Google declined to comment, as did the Justice Department.

The backdrop: The Federal Trade Commission previously directed a separate Google antitrust investigation, looking at the company's search and advertising practices and the negative impact on competitors. However, the probe was dropped in 2013. The company chose to make a handful of changes as a result.

Go deeper: Tech's regulation debate moves from "whether" to "how"