Tesla is under criminal investigation in the U.S. over claims that the company's electric vehicles can drive themselves, Reuters reported, citing three people familiar with the matter.

The U.S. Department of Justice launched the previously undisclosed probe In 2021, following more than a dozen crashes, some of them fatal, involving Tesla's driver assistance system Autopilot, which was activated during the accidents, the people said.

Tesla's marketing materials have been touting the now-embroiled Autopilot's capabilities since 2016, when Tesla himself made claims about the function on a conference call.

Last week, Elon Musk, the Silicon Valley automaker's chief executive, said on another call that Tesla would soon release an upgraded version of "Full Self-Driving" software allowing customers to travel "to your work, your friend's house, to the grocery store without you touching the wheel."

Legal challenges for a potential lawsuit

A promotional video currently on the company's website says, "The person in the driver's seat is only there for legal reasons. He is not doing anything. The car is driving itself.

However, the company also has explicitly warned drivers that they must keep their hands on the wheel and maintain control of their vehicles while using Autopilot. 

"Autopilot, Enhanced Autopilot and Full Self-Driving Capability are intended for use with a fully attentive driver, who has their hands on the wheel and is prepared to take over at any moment. While these features are designed to become more capable over time, the currently enabled features do not make the vehicle autonomous," the company says on its website.

It also warns that "before enabling Autopilot, the driver first needs to agree to 'keep your hands on the steering wheel at all times' and to always 'maintain control and responsibility for your vehicle.'" The site further states that "every time the driver engages Autopilot, they are shown a visual reminder to 'keep your hands on the wheel.'"

Such warnings could complicate any case the Justice Department might wish to bring, the sources said.

Barbara McQuade, a former U.S. attorney in Detroit who prosecuted automotive companies and employees in fraud cases and is not involved in the current probe, said investigators likely would need to uncover evidence such as emails or other internal communications showing that Tesla and Musk made misleading statements about Autopilot's capabilities on purpose.

Tesla, which disbanded its media relations department in 2020, did not respond to written questions from Reuters on Wednesday. Musk also did not respond to written questions seeking comment. A Justice Department spokesperson declined to comment.