TuSimple Holdings Inc. co-founder Mo Chen has taken control of the self-driving trucking company as federal authorities continue to investigate TuSimple's relationship with Mr. Chen's other startup, a Chinese hydrogen-trucking company. A TuSimple filing with the Securities and Exchange Commission on Wednesday shows that Mr. Chen has 59% of the voting power at the San Diego-based company, giving him control as of Nov. 9, a day before the company announced it had ousted its board of directors. Mr. Chen acquired the stake through stock purchases using his family trust and British Virgin Islands-based entities, according to the securities filing. TuSimple's newly appointed chief executive officer, Cheng Lu, said, "We have a strong sense of urgency to put our company back on track and regain trust from all stakeholders." A weekly digest of tech reviews, headlines, columns and your questions answered by WSJ's Personal Tech gurus.

TuSimple Holdings Inc., a U.S.-based self-driving trucking company, faces federal investigations into whether it improperly financed and transferred technology to a Chinese startup, according to people with knowledge of the matter. The people said the concurrent probes by the Federal Bureau of Investigation, Securities and Exchange Commission and Committee on Foreign Investment in the U.S., known as Cfius, are examining TuSimple's relationship with Hydron Inc., a startup that says it is developing autonomous hydrogen-powered trucks and is led by one of TuSimple's co-founders. Investigators at the FBI and SEC are looking at whether TuSimple and its executives--principally Chief Executive Xiaodi Hou--breached fiduciary duties and securities laws by failing to properly disclose the relationship, the people familiar with the matter said. They are also probing whether TuSimple shared with Hydron intellectual property developed in the U.S. and whether that action defrauded TuSimple investors by sending valuable technology to an overseas adversary, the people said. A personal, guided tour to the best scoops and stories every day in The Wall Street Journal.