Earlier this year, Luminar founder and CEO Austin Russell abruptly resigned from his position after it was revealed he was the target of an ethics inquiry. Now, the 30-year-old billionaire is trying to wrest back control of his old company, which made him a fortune by designing lidar sensors of self-driving cars.

According to an SEC filing (and first reported by TechCrunch), Russell wants to acquire “100% of the outstanding shares of the Class A Common Stock” in Luminar under the auspices of his new company, Russell AI Labs. The new company would still be publicly listed (Luminar went public through a reverse SPAC merger in 2020) and traded under the same “LAZR” ticker symbol.

Russell says in the filing he was invited to acquire the company “at the suggestion of certain shareholders and the invitation of certain members of the board of directors” of Luminar. At the time, Luminar didn’t explain the reason for Russell’s departure, nor has it said whether the ethics inquiry turned anything up.

Russell founded his new venture in September along with Markus Schaefer, CTO of Mercedes-Benz Group AG, and Murtaza Ahmed, former managing partner at Softbank. Meanwhile, Luminar has encountered financial difficulties over the past year, has gone through several rounds of layoffs, and was nearly delisted from the NASDAQ.