The Federal Trade Commission (FTC) is investigating Tesla Inc. Chief Executive Elon Musk’s initial 9 percent stake purchase in Twitter Inc., according to The Information on Thursday.

According to people familiar with the situation, the FTC is investigating whether Musk complied with an antitrust reporting requirement when he purchased his stake in the social media company in early April.

According to the report, the focus of the investigation is whether Musk purchased the stake to influence Twitter’s management or if he appeared to be a passive shareholder.

Twitter stated that it had no comment on the report, and the FTC declined to comment.

In an April 4 filing with the US Securities and Exchange Commission, the world’s richest person described his stake as passive.

He later offered to buy the company for $54.20 per share in cash, an offer that Twitter accepted earlier this week.