Tesla on Tuesday won the first US trial over allegations that its Autopilot driver assistant feature led to a death, as a jury found there was not a manufacturing defect in the system.

The case, in a California state court, was filed by two passengers in a 2019 crash who accused the company of knowing Autopilot was defective when it sold the car. Tesla argued human error caused the crash.

The civil lawsuit alleges the Autopilot system caused owner Micah Lee's Model 3 to suddenly veer off a highway east of Los Angeles at 105 kilometres per hour, strike a palm tree and burst into flames, all in the span of seconds.

The 2019 crash killed Lee and seriously injured his two passengers, including a then-eight-year-old boy who was disemboweled, court documents show. The lawsuit, filed against Tesla by the passengers, accuses the company of knowing that Autopilot and other safety systems were defective when it sold the car.

Tesla denied liability, saying Lee consumed alcohol before getting behind the wheel. The electric-vehicle maker also claims it was unclear whether Autopilot was engaged at the time of the crash.

Tesla has been testing and rolling out its Autopilot and more advanced Full Self-Driving (FSD) system, which Chief Executive Elon Musk has touted as crucial to his company's future but which has drawn regulatory and legal scrutiny. (Reuters)