An investigation has been launched in the US into more than half a million Tesla cars that are equipped with touchscreens.

It follows a complaint filed by a user who discovered he could play games while driving.

The US National Highway Traffic Safety Administration (NHTSA) is looking into some 580,000 Tesla Models 3, S and X made from 2017 to the current day.

Tesla has not yet responded to the investigation.

The feature under scrutiny is called Passenger Play, and it allows users to play games on their in-car touchscreen.

It does warn that playing while in motion is "only for passengers" and asks for confirmation of this before allowing gameplay.

But the NHTSA noted that Passenger Play "may distract the driver and increase the risk of a crash".

It added that the feature had been available since December 2020. Previously the game feature was only enabled when the vehicle was in Park mode.

Earlier this month the NHTSA reported that 3,142 road deaths in 2019 were attributed to distracted drivers.

Guidelines published by the agency in 2013 recommend that in-vehicle devices be designed so that they cannot be used by the driver "to perform inherently distracting secondary tasks while driving".

Last month, Tesla owner Vince Patton from Oregon spotted a video on YouTube which highlighted how Passenger Play could be used by drivers.

After testing it in a car park and finding he could indeed play several games while driving, he filed a complaint with the NHTSA, describing the feature as "recklessly negligent".

Earlier this month, Mercedes-Benz issued a recall for an issue caused by a computer configuration error that allowed drivers to browse the internet or watch television while the cars were moving.