Former head of Uber’s self-driving car project Anthony Levandowski was warned that his employment would be terminated if he did not comply with case

Uber has threatened to fire Anthony Levandowski, the former Google engineer at the centre of Uber’s court case with Alphabet’s Waymo, accused of stealing self-driving car trade secrets.

Waymo sued Uber alleging that Levandowski, one of the former engineers key to the development of Google’s self-driving cars, downloaded more than 14,000 confidential documents before leaving Waymo to start self-driving truck firm Otto, which was subsequently bought by Uber.

According to a court filing, Uber told Levandowski that he must comply with an order to return Waymo documents or face possible termination.

Uber general counsel, Salle Yoo, wrote in a letter to Levandowski: “If you do not agree to comply with all of the requirements set forth herein, or if you fail to comply in a material manner, then Uber will take adverse employment action against you, which may include termination of your employment.”

The case, which pits the two companies battling for dominance in the fast-growing field of self-driving cars, hinges on Waymo’s allegations that data taken by Levandowski made its way into a key sensor system for self-driving cars called Lidar.

Uber was issued with an injunction last week by US district judge William Alsup in San Francisco, ordering it to keep Levandowski away from work involving Lidar, which is used for range detection and environment scanning among other things. The injunction ordered Uber to prevent Levandowski and all other employees from using any Waymo materials and to return them to the Alphabet-owned company by 31 May.

Levandowski lawyers asked the judge to modify his order so that Uber is not required to fire the engineer if he asserts his constitutional rights against self-incrimination and refuses to produce documents. Waymo declined to comment and Uber did not respond to a request for comment.

Uber said it would appeal against a judge’s order rejecting its attempt to arbitrate Waymo’s trade secret claims, according to a court filing on Thursday. Alsup blocked Uber’s efforts to have the lawsuit heard in a private forum, ruling that it should continue to be litigated in San Francisco federal court.

Levandowski left Waymo in January 2016 and started Otto, a self-driving truck startup that Uber bought for $680m (£523m) in August. He ran Uber’s self-driving car division before stepping aside from those responsibilities pending the court case last month.

Uber has not denied that Levandowski took Waymo documents, but says it has not used any Waymo technology in its cars. In his injunction order, Alsup said “few” of Waymo’s alleged trade secrets have been traced to Uber’s self-driving car technology, and that Waymo’s patent claims against Uber have proved meritless.