Uber has threatened to fire Anthony Levandowski, the former Waymo engineer at the center of a legal drama, if he doesn't comply with court orders to turn over allegedly stolen files.

Levandowski is said to have taken more than 14,000 documents from Alphabet's self-driving car unit, Waymo, when he exited the company to launch his own startup. That startup, Otto, was acquired by Uber just months later.

Waymo filed a lawsuit against Uber in February. A trial is set for October in the U.S. District Court for the Northern District of California in San Francisco.

Salle Yoo, Uber's general counsel, sent a letter to the executive earlier this week, which insisted that he comply with an investigation into the matter and disclose handling of files by Uber employees. The letter was made public in a court on Thursday.

Thus far, Levandowski has consistently invoked his Fifth Amendment rights. Uber and Waymo both declined to comment when reached by the Wall Street Journal. Last week, a judge insisted that Uber shouldn't "pull any punches" in compelling Levandowski to comply with orders.