Some app developers say Google LLC is increasingly pressing them to embed code in their own products that will deepen Google's access to data on consumers, giving the company a leg up on rivals.

The previously unreported concerns about Firebase, a set of software that Google makes available to apps, have become part of the broad investigations launched last summer by state attorneys general and the United States Department of Justice into whether Google has unlawfully stifled competition in online advertising and other businesses, two people with knowledge of the probes said this month.

The Texas attorney general's office, which is leading the states' investigation, and the Justice Department did not respond to requests to comment.