Google’s self-driving car arm has warned that Tesla’s cost-cutting drive could prove to be “very, very risky” for the safety of its autonomous vehicles.

Waymo’s head of research has warned that Elon Musk’s refusal to add a piece of technology that is relied upon by many self-driving start-ups to save money could leave it open to errors that might endanger people.

Autonomous vehicles rely on an array of sensors and cameras to observe and “learn” from their surroundings, allowing them to make operational decisions and avoid obstacles.

One sensor is a Light Detection and Ranging (Lidar) that uses lasers to measure range to create a 3D image. Lidars have become a standard piece of kit on the cars, but are cumbersome, unattractive – and, according to Musk, too expensive.