Tesla Inc. Chairman and CEO Elon Musk’s surprise announcement via tweet last week that he was considering bringing his electric car manufacturing company private and had secured funding has led to two putative class action lawsuits filed against him and his firm.

The litigation focuses own whether Mr. Musk has in fact secured funding for his plan and accuses him of violating securities laws. Mr. Musk defended himself in a blog post Monday.

One lawsuit was filed by William Chamberlain against Palo Alto, California-based Tesla and Mr. Musk in U.S. District Court in Oakland, California, while a second was filed in San Francisco against the same defendants, according to William Chamberlain v. Tesla Inc. and Elon Musk and Kalman Isaacs v. Elon Musk and Tesla Inc.

While the company’s stock price increased immediately after the announcements, it has declined following reports that the Securities and Exchange Commission is investigating the situation.

According to these reports, the SEC has asked Tesla about the facts of the matter, why it was disclosed on Twitter rather than in a regulatory firing, and whether investor-protection rules had been met. 

Both lawsuits say Mr. Musk made false and misleading statements. The Chamberlain lawsuit states “even Tesla’s board of directors has no evidence that funding has been secured for what has been reported could be the largest corporate buyout in history and require securing tens of billions of dollars for a company whose debt ratings occupy junk status.”

The Issacs lawsuit states, “For many reasons, it is not possible for defendant Musk to have secured funding for the deal. First, it would be hard for Musk to raise the equity and debt financing needed for the deal (approximately $72 billion) given Tesla is not turning a profit. Indeed, the Company is currently cash-flow negative. How then could Tesla issue tens of billions of dollars of new debt when it is cash-flow negative?”

A Tesla spokesman could not be reached for comment on the litigation. However, in a blog post Monday, which does not address the lawsuits, Mr. Musk defends his actions and states it “was clear to me the right thing to do was announce my intentions publicly.”

Mr. Musk also said that following a July 31 meeting with Saudi Arabia’s sovereign wealth fund, he had “no question” a deal would be secured, and it was “just a matter of getting the process moving.”