Anthony Levandowski, Otto Co-founder and VP of Engineering at Uber.

Angela Merendino | AFP | Getty Images

Anthony Levandowski, Otto Co-founder and VP of Engineering at Uber.

The U.S. judge overseeing a blockbuster case over self-driving car technology suggested Uber could face an injunction if a key Uber executive does not testify for fear of exposing himself to criminal prosecution, according to a transcript seen by Reuters.

Waymo, the self-driving car unit of Alphabet, sued ride services company Uber Technologies last month, alleging that a former Waymo executive, Anthony Levandowski, downloaded over 14,000 confidential documents before leaving the company to subsequently join Uber. Waymo said Uber benefited from those documents.

Levandowski is not a defendant in the case, but he is a central figure in the high-profile litigation that pits two Silicon Valley technology giants against each other, both of which are vying to dominate in the competitive autonomous vehicles sector.

Waymo is seeking a preliminary injunction from the court, which would temporarily stop Uber from using any of the allegedly stolen intellectual property. A hearing is scheduled for May 3.

Uber, which has said the allegations are baseless but has not yet responded to Waymo’s complaint in court, has argued that the trade secrets issue should be sent to arbitration.

“You represent somebody who’s in a mess,” U.S. District Court Judge William Alsup in San Francisco told the attorney for Levandowski, Miles Ehrlich, during a closed court hearing on Wednesday. Reuters saw the transcript of that hearing.

Ehrlich had told the court that based on the “potential for criminal action” against Levandowski, the engineer would be asserting his Fifth Amendment rights against self-incrimination.

Contacted on Thursday, Ehrlich denied further comment. Uber did not respond to a request for comment.