Already beset by multiple recalls of its ATVs, Polaris is now facing an investigation by the feds into the safety of its flagship road vehicle.

The Minnesota-based company will be under the microscope of the National Highway Traffic Safety Administration after the death of a driver behind the wheel of a 2015 Polaris Slingshot in Michigan.

The driver of the three-wheel roadster – which can go from 0-60 mph in less than 5 seconds and has a top speed of 130 mph – died when the Slingshot slid during a lane change and was hit by an oncoming vehicle, the NHTSA says.

But despite wearing his seatbelt, the driver was found "partially ejected" from his seat.

Investigators are looking into whether an apparent defect with the belt caused it to release during the crash, sending the driver out of his seat.

It has opened a "preliminary evaluation" to determine if this defect is not exclusive to this one model.

Post-crash pictures showed that the Slingshot’s seatbelt retractor was "in a shattered condition with the internal components found outside the retractor body," according to NHTSA.

The driver, who was also wearing a helmet, died from a severed spinal cord, Bloomberg reports.

The probe into the Slingshot will cover 4,779 models produced in 2015. The company did not respond to Bloomberg when asked for comment.