The driver of a Tesla involved in a fatal crash that California highway authorities said may have been operating on autopilot, posted social media videos of himself in the vehicle without his hands on the wheel or foot on the pedal.
The crash on May 5 in Fontana, 50 miles east of Los Angeles, in the US, is also under investigation by the National Highway Traffic Safety Administration.
The probe is the 29th case involving a Tesla that the federal agency has investigated.
In the Fontana crash, a 35-year-old man identified as Steven Michael Hendrickson was killed when his Tesla Model 3 hit an overturned lorry at about about 2.30am.
Mr Hendrickson was a member of the Southern California chapter of a Tesla club who posted numerous photos and video on social media of his white Model 3.
One video on his Instagram account showed him in the driver’s seat without his hands on the wheel or foot on the pedal as the Tesla navigated traffic.
The video included the comment: “Best carpool buddy possible even takes the boring traffic for me.”
Another man was seriously injured when the electric vehicle hit him as he was helping the lorry’s driver out of the wreck.
The California Highway Patrol said on Thursday that its preliminary investigation had determined that the Tesla’s partially automated driving system, called Autopilot, “was engaged” prior to the crash.
The agency said it was commenting on the Fontana crash because of the “high level of interest” about Tesla crashes and because it was “an opportunity to remind the public that driving is a complex task that requires a driver’s full attention”.
However on Friday the agency said: “To clarify, there has not been a final determination made as to what driving mode the Tesla was in or if it was a contributing factor to the crash.”
At least three people have died in previous US crashes involving Autopilot, which can keep a car centred in its lane and a safe distance behind vehicles in front of it.
Tesla is allowing a limited number of owners to test its self-driving system.
The company says in owner’s manuals and on its website that both Autopilot and “Full Self-Driving” are not fully autonomous and that drivers must pay attention and be ready to intervene at any time.