Tesla is under investigation over accusations that it misused company funds to work on a secret glass house project for CEO Elon Musk, the Wall Street Journal reported on Wednesday.
The project is being investigated by US prosecutors as well as the Security Exchange Commission (SEC), the markets regulator, the report said.
The Wall Street Journal had earlier reported that Tesla employees had complained to the company's board about the project, which is known as Project 42, and that an internal investigation was carried out.
The plans called for a spacious glass building to be erected near the electric vehicle company's Austin-area headquarters.
The investigations were in their early stages and will not necessarily result in charges being made, the report said.