U.S. NHTSA asks Tesla why it did not recall autopilot system

U.S. National Highway Traffic Safety Administration (NHTSA) has asked Tesla Inc why the electric-car maker has not filed recall paperwork after updating its autopilot driving system, the Associated Press reported on Wednesday.

U.S. highway safety investigators told the company that it must to do a recall if an over-the-internet software update mitigates a safety defect, the Associated Press reported, citing an NHTSA letter sent to Tesla on Tuesday.