Investing.com -- The U.S. Securities and Exchange Commission on Thursday sued Elon Musk on Thursday to force him to provide testimony in the agency's probe into his purchase of Twitter last year.

The SEC alleges that Musk failed to appear to provide testimony on a Sept. 15, and said that the filing of the subpoena, with the U.S. District Court for the Northern District of California, is "seeking an order compelling compliance."

In the complaint, lawyers for the SEC wrote that the "Musk's ongoing refusal was hindering and delaying" the agency's probe into whether federal securities laws were violated in the purchase of Twitter.

The testimony subpoena to Musk relates to an ongoing investigation by the SEC into potential violations of federal securities laws relating to Musk’s 2022 purchases of Twitter stock, and his 2022 statements and SEC filings relating to Twitter, according to the court filing.

"The SEC has already taken Mr. Musk's testimony multiple times in this misguided investigation - enough is enough," Reuters reported, citing a statement from Alex Spiro, an attorney for Musk.