BMW AG's Mini Cooper cars are under investigation by U.S. safety regulators for possible defects that can cause the power steering to fail, raising the risk of a crash, Bloomberg reported.

Mini Coopers from model years 2004 and 2005 have been the subject of 54 complaints about unexpected power-steering loss, the National Highway Traffic Safety Administration said today on its website. An estimated 80,000 vehicles are subject to the U.S. investigation.

The company will provide information sought by the safety agency, BMW spokesman Tom Kowaleski said.

In July, NHTSA opened an investigation into the BMW Z4's power steering following 107 complaints and one crash involving vehicles from the 2003 to 2005 model years.

Mini Cooper drivers in their complaints to the regulator reported intermittent power-steering failure that technicians were unable to replicate.