(Krisztian Bocsi/Bloomberg News)

Google said Friday that the Justice Department has requested records related to its prior antitrust investigations, marking the tech giant’s first major acknowledgment that it’s a subject of a federal competition probe.

The civil-investigative demand — acknowledged in a securities filing and a blog post — comes weeks after Justice Department officials said they would open a broad review of big tech, including search. It also comes days before more than 30 state attorneys general are expected to announce a major antitrust investigation of Google, as The Washington Post first reported.

“We have answered many questions on these issues over many years, in the United States as well as overseas, across many aspects of our business, so this is not new for us,” wrote Kent Walker, Google’s senior vice president of global affairs. “The DOJ has asked us to provide information about these past investigations, and we expect state attorneys general will ask similar questions. We have always worked constructively with regulators and we will continue to do so.”

The Justice Department declined to comment. The agency’s top antitrust official, Makan Delrahim, signaled that such requests could be coming to tech giants as part of the department’s review, which is also focused on social networking and e-commerce.

“We might be issuing compulsory process on some third parties who may or may not need it, for whatever reason, to provide more information to us,” he said last month.

For now, Google said that the Justice Department sought “information and documents relating to our prior antitrust investigations in the United States and elsewhere.” That could give department lawyers a critical early trove of data to start their work.

The U.S. government’s other antitrust agency, the Federal Trade Commission, previously investigated Google’s search and advertising businesses for violations of antitrust law, but regulators there concluded their probe in 2013 without issuing major punishments against the tech giant.

The European Union, however, has been much tougher on Google: Antitrust authorities for the region have slapped the company with a total of $9 billion over the past three years for harming competition and consumers. E.U. officials have faulted Google for giving better billing in search results to its own offerings over rivals, for example, and using unfair practices in deploying its Android smartphone operating system.