Tesla CEO Elon Musk on Thursday called the SEC's allegations of fraud "unjustified" and said he acted in the best interests of investors.

"This unjustified action by the SEC leaves me deeply saddened and disappointed," Musk said in a statement to CNBC. "I have always taken action in the best interests of truth, transparency and investors. Integrity is the most important value in my life and the facts will show I never compromised this in any way."

The SEC sued Musk earlier Thursday, alleging the billionaire CEO made "false and misleading" statements surrounding an Aug. 7 take-private tweet.

In the tweet, Musk said he was considering taking Tesla private, adding "funding secured." The SEC complaint alleges Musk made that claim knowing it was false and without the input of other Tesla executives.

@elonmusk: Am considering taking Tesla private at $420. Funding secured.

Musk called off the privatization plans on Aug. 24, saying it had become apparent that "most of Tesla's existing shareholders believe we are better off as a public company."

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