Reports of Tesla Model X seatbelts coming loose while driving prompts NHTSA investigation

The National Highway Traffic Safety Administration has opened an investigation into reports of seat belts allegedly detaching in Teslas while driving.

The investigation, which was opened on Friday, covers an estimated 50,000 Tesla Model X SUVs from the 2022 and 2023 model years.

According to NHSTA documents, the agency's Office of Defects Investigation received two complaints from Tesla owners who reported that their front seat belts failed to remain connected "while driving with seat belts worn properly."

"Both vehicles were delivered to the owners with insufficiently connected anchor linkages," NHSTA wrote. The agency said the front belts weren’t properly connected during the Teslas' assembly.

The front seat belt linkage and pretensioners, which tighten the belts before a collision, are anchored to the seat frames, the agency said.

"The linkage and the pretensioner suddenly separated when the force exerted on the linkage overcame the resistance of the friction fit while the vehicles were in motion," NHSTA said.

Neither incident involved a car crash, the agency said. Both vehicles had low vehicle mileage at the time of the reported seat belt detachment.

NHSTA said its probe will look into Tesla's manufacturing process, as w assess the scope of the issue. USA TODAY reached out to Tesla for statement on Tuesday.

Another Tesla probe: Regulators investigating reports Tesla steering wheels falling off in some models 

Tesla recall: Thousands of Model Y vehicles recalled over loose bolts in seat back frames 

More car recalls: Over 807,000 cars from Hyundai, Kia, Mercedes-Benz and GM under recall 

NHSTA's investigation into the alleged Tesla seat belt detachment comes just weeks after the agency opened another probe into 2023 Model Y vehicles, following two complaints that the SUV’s steering wheels could come off while people were driving.

NHTSA is investigating additional complaints into Teslas dating back several years – including probes into reports of partially automated driving systems that can brake without reason or run into emergency vehicles parked on highways.

NHSTA investigations can lead to car recalls. As of Tuesday, officials had not initiated a recall for 2022 and 2023 Model X SUVs over the seat belt detachment reports.

Still, other Tesla drivers have been facing recalls in recent months – including a November recall of 2021-2023 Tesla Model X cars over the potential of the front passenger airbag system deploying incorrectly during some collisions, requiring a software update to solve the risk.

Earlier this month, Tesla initiated a recall of 2022-2023 Model Y vehicles in the U.S. because bolts in the second-row seats may be loose. Owners of the recalled vehicles were instructed to take their car to a Tesla service center, to inspect and tighten the bolts.

What's everyone talking about? Sign up for our trending newsletter to get the latest news of the day. 

Contributing: The Associated Press. Marina Pitofsky, Jordan Mendoza and Natalie Neysa Alund, USA TODAY.

This article originally appeared on USA TODAY: Tesla Model X SUV seat belts coming loose subject of US investigation