U.S. safety regulators are investigating the recall of 1.7 million Hyundai and Kia vehicles due to whistleblower reports that the recalls may have been mishandled.

About the Hyundai and Kia Recalls

According to Reuters, the recall was originally issued in 2015 and covered 470,000 Hyundai Sonatas which suffered from an engine defect which could result in the vehicles stalling while in operation, increasing the risk of crash.

However, a Hyundai engineer, Kim Gwang-ho, flew to Washington in August 2016 to inform the National Highway Traffic Safety Administration (NHTSA) that the recall should cover more vehicles and to report several alleged safety lapses.

The Hyundai Kia Automotive Group has since expanded the recall to cover an additional 572,000 Hyundai vehicles and 618,160 Kia vehicles.

Fines could be imposed on the automakers should the federal investigation result in evidence of wrongdoing.

Vehicles Affected by the Hyundai and Kia Recalls

The following vehicles are included in the engine stall recall:

• 2011-2014 Hyundai Sonata
• 2013-2014 Hyundai Sante Fe Sport
• 2011-2014 Kia Optima
• 2012-2014 Kia Sorento
• 2011-2013 Kia Sportage