Tesla is vigorously disputing claims that its vehicles suffer from unintended acceleration issues after it was revealed the National Highway Traffic Safety Administration (NHTSA) will look into a petition (see full document here) asserting about 500,000 of its electric cars may have such problems.

In a blog post, Tesla revealed that the petition was filed by a Tesla short-seller by the name of Brian Sparks. In the petition, Sparks said Tesla owners have lodged 127 complaints with the government, covering 110 crashed and 52 injuries. It has been confirmed that Sparks is indeed a short-seller of Tesla’s shares.

Related: Tesla Might Have An Unintended Acceleration Issue As Regulators Investigate Over 120 Claims

“We investigate every single incident where the driver alleges to us that their vehicle accelerated contrary to their input, and in every case where we had the vehicle’s data, we confirmed that the car operated as designed,” Tesla wrote in its blog post. “In other words, the car accelerates if, and only if, the driver told it to do so, and it slows or stops when the driver applies the brake.”

The petition filed by Sparks includes Model S vehicles from the 2012-2019 model years, Model Xs from the 2016-2019 model years, and Model 3s from the 2018 and 2019 model years.

In the blog post, Tesla added that its vehicles have systems in place should drivers mistakenly press the accelerator.

“While accidents caused by a mistaken press of the accelerator pedal have been alleged for nearly every make/model of vehicle on the road, the accelerator pedals in Model S, X and 3 vehicles have two independent position sensors, and if there is any error, the system defaults to cut off motor torque,” it wrote. “Unique to Tesla, we also use the Autopilot sensor suite to help distinguish potential pedal misapplications and cut torque to mitigate or prevent accidents when we’re confident the driver’s input was unintentional. Each system is independent and records data, so we can examine exactly what happened.”

The NHTSA has yet to verify the complaints, ABC News reports.