At least four car companies’ data collection and sharing practices are under investigation by the Texas attorney general’s office for potentially violating state law on deceptive trade practices, according to documents obtained by Recorded Future News.

Kia, General Motors, Subaru and Mitsubishi received “civil investigative demand” letters from the office’s consumer protection division in late April.

It’s the first known request for documents from connected car companies by a state investigative body as part of an enforcement review, experts say.

The California Privacy Protection Agency announced it would probe the data collection and sharing practices of connected-car companies and technologies in July, but the status of that inquiry is unknown.