The driver of the Tesla involved in the deadly crash informed police that he was using Autopilot and checking his phone at the time of the incident

The driver of a Tesla involved in a crash that left a motorcyclist dead said he was operating the vehicle’s Autopilot feature and checking his phone at the time, documents show.

The 56-year-old unnamed driver was on his way home from lunch at 3.45pm last Friday when his Tesla collided with a motorcycle driven by Jeffrey Nissen, 28, in a suburban area about 15 miles outside of Seattle. Mr Nissen was pronounced dead at the scene.

Authorities are yet to verify that the car was running Autopilot at the time of the crash, but the fatal incident raises questions over whether Tesla’s recent recall of two million cars went far enough to ensure that motorists using the auto drive feature pay attention to the road.

The Tesla driver was arrested for investigation of vehicular homicide after he told a Washington State Patrol trooper he was using the vehicle’s Autopilot feature and looked at his cellphone while the car was moving, according to a probable-cause document obtained by the Associated Press.

The affidavit stated that the driver was arrested “based on the admitted inattention to driving, while on Autopilot mode, and the distraction of the cell phone while moving forward, putting trust in the machine to drive for him”.

“The next thing he knew, there was a bang, and the vehicle lurched forward as it accelerated and collided with the motorcycle in front of him,” the trooper wrote in the document.

Washington State Patrol Captain Deion Glover said on Wednesday that the investigation is in its “early stages” and is yet to establish whether Autopilot was on at the time.

Four months ago, Tesla recalled more than two million vehicles to work on the system that is supposed to ensure drivers are paying attention while using Autopilot.

The company sent out a software update after a National Highway Traffic Safety Administration investigation found that Autopilot’s method of ensuring drivers are paying attention while using Autopilot can be inadequate.

Tesla said in government documents last year that the software change would increase warnings and alerts to drivers to keep their hands on the steering wheel.

Tesla states on its website that Autopilot is intended “for use with a fully attentive driver, who has their hands on the wheel and is prepared to take over at any moment,” and that the features do not make the vehicle autonomous.

Before Autopilot is enabled, the driver must agree to keep their hands on the wheel at all times, and a visual reminder to do so can be seen when Autopilot is engaged.

The driver must also “maintain control and responsibility for your vehicle,” Tesla writes on its website.

Mr Nissen’s sister, Jenessa Fagerlie, is now preparing along with her other siblings for the cremation of her brother, who she said was taken too soon.

"Honestly, just losing my brother is the worst part," Nissen’s sister, Jenessa Fagerlie, told Fox13. "I didn’t even imagine it would go this way."

Ms Fagerlie has set up a GoFundMe page to raise funds for her brother’s funeral.

Ms Fagerlie pleaded with people driving to keep aware while driving. "You still need to pay attention to the road," she said.

James Smith