The US Department of Justice is investigating Tesla over statements made by CEO Elon Musk concerning his desire to take the company private, according to Bloomberg. Federal prosecutors opened a fraud investigation last month after Musk tweeted that he was contemplating taking Tesla private and had “funding secured” for the deal, several sources told the publication. Weeks later, the deal fell through, and Musk announced that Tesla would remain public.

The Securities and Exchange Commission is already probing Musk’s electric car company over whether he misled investors and violated federal securities laws with his public statements. The agency was also investigating Tesla for possibly misleading investors about its Model 3 production. But both of those investigations are civil in nature, while the Justice Department inquiry could result in criminal charges. Tesla faces at least three investor lawsuits that accuse Musk’s August 7th tweet of being market manipulation.

Updated September 18th 1:09pm ET: A spokesperson for Tesla responded with a statement: “Last month, following Elon’s announcement that he was considering taking the company private, Tesla received a voluntary request for documents from the DOJ and has been cooperative in responding to it. We have not received a subpoena, a request for testimony, or any other formal process. We respect the DOJ’s desire to get information about this and believe that the matter should be quickly resolved as they review the information they have received.”