People familiar with the matter saidAntitrust investigators from the U.S. Department of Justice have stepped up their response in recent months.GoogleThe inspection of the digital advertising business shows that the Biden administration is actively promoting an investigation that began under former President Donald Trump.

People familiar with the matter, who spoke on condition of anonymity during the early investigation, said antitrust office staff interviewed several Google competitors to learn about Google's practices in the advertising technology market and target the company's second-largest and most important business.

The Justice Department sued Google last year, claiming that Alphabet Inc. The subsidiary abused its dominant position in the field of Internet search. Any additional legal action, including the filing of a second lawsuit, could depend on who is chosen by President Joe Biden to lead the antitrust department as the assistant attorney general. At that time, it will be up to this person to decide whether to proceed or not, and it is possible that the government will not take any action against the company.

The government is also gathering evidence from existing lawsuits and investigations in other jurisdictions, focusing on Google's business of placing ads on other sites, one of the people familiar with the matter said. The Justice Department declined to comment. A Google representative didn't immediately respond to a request for comment.