The U.S. Federal Trade Commission has asked Twitter Inc. to turn over internal communications related to owner Elon Musk, detailed information about layoffs and other business decisions as part of an investigation into the social media company, The Wall Street Journal reported Tuesday, citing documents.

The FTC sent 12 letters to Twitter and its lawyers since Musk's takeover in October. It also asked the company to "identify all journalists" who were granted access to company records and to provide information about the launch of the revamped Twitter Blue subscription service, the report said.

The FTC is also looking to get Musk to testify in connection with the probe, WSJ reported.

Twitter, the FTC and Musk did not immediately respond to Reuters' requests for comment.