The officials assessing whether Elon Musk violated federal securities law during his acquisition of Twitter are growing tired of his alleged attempts to stall their investigation. In a new filing on Wednesday, the US Securities and Exchange Commission (SEC) accused Musk of trying to “misrepresent” the scope of its investigation, claiming that he “persists with baseless constitutional objections” against its attempts to make him testify.

The SEC has been scrutinizing Musk since 2022 over his delay in disclosing a substantial stake in Twitter. Musk had purchased before initiating his acquisition of the social media platform on April 14th. According to the SEC, while Musk testified twice that year, he has since fought against a third and final attempt to interview him, accusing the regulator of “harassment” when it sued him in October last year for refusing to testify.

On February 10th, a federal judge ordered Musk to cooperate in the SEC’s investigation, asserting that if a date and location for the interview couldn’t be agreed upon between the parties within a week then the decision would be made for them. That testimony has yet to take place, with the SEC now accusing Musk of using “gamesmanship” to hinder its investigation.

The Commission claims that following its attempt in April 2023 to schedule Musk’s final session of testimony, he “has done everything he can to delay the completion of this matter. Musk now complains that this investigation has been pending for too long, but it was Musk’s delay tactics that have turned one year into almost two.”

Interestingly, the SEC filing also mentions that Walter Isaacson’s biography on Musk — which allegedly “provides important new information” relevant to the investigation — was published three days before he failed to show up for testimony in September 2023. That same book is also being referenced in a lawsuit raised by several of the top Twitter executives Musk fired shortly after he acquired the company.