An electric Tesla car driving under autopilot along the Autobahn near Gudow, Schleswig-Holstein has collided with a travel bus, police reported on Thursday.
The Danish travel, which had 29 people on board, had overtaken a truck and was trying to get back into the right lane when the collision occurred.
The Tesla car, which belongs to a 50-year-old man from Brandenburg, hit the bus from behind.
The driver said that he had been using the autopilot function.
A Tesla spokesperson however said in a statement that "we have spoken to our customer, who confirmed that autopilot was functioning properly and that his use of autopilot was unrelated to the accident. We're glad that he's safe."
Tesla cars transmit driving data to the manufacturer so that the company usually can find out if and how the self-driving feature was used.
Police confirmed that the car had been on autopilot mode and said that there now must be an investigation of why the function did not prevent the accident.
The Tesla driver was only slightly injured due to the collision and police reported that “all those on board the travel bus escaped with no more than a scare”.
The damage from the incident is estimated at €55,000.
Elsewhere in the world, there have been various reports of the Tesla's self-driving feature not working and resulting in crashes since the company introduced it in October last year.
The first fatal crash involving the self-driving system occurred in May in Florida, when a semi-truck drove in front of a Tesla Model S. The autopilot system did not brake because Tesla said the system did not notice the white side of the larger vehicle against the bright sky.
The Florida case attracted the attention of a US Senate Committee, which demanded a briefing on the autopilot's role in the accident.
Consumer activists have called on the company, founded by PayPal billionaire Elon Musk, to disable the autopilot feature until it is updated to detect whether the driver's hands are on the steering wheel during operation, as the company says they ought to be.
The driver in Wednesday's crash told police that he had not removed his hands from the wheel while the autopilot was activated.
Germany has been testing out self-driving technology itself, reserving a section of the Autobahn in Bavaria to experiment with fully-automated cars.