SAN FRANCISCO (Reuters) - A U.S. judge on Wednesday warned Uber Technologies Inc it could face a court injunction that would bar a key Uber executive from working on its self-driving car project, in a high-profile case filed by Alphabet Inc’s Waymo unit.

FILE PHOTO: A man arrives at the Uber offices in Queens, New York, U.S., February 2, 2017. REUTERS/Brendan McDermid/File Photo

The litigation pits two Silicon Valley giants against each other over technology at the heart of a potential revolution in the auto industry.

U.S. District Judge William Alsup said evidence amassed by Waymo to bolster its case of being robbed was extraordinary.

“I’ve never seen a record this strong in 42 years,” Alsup said. A hearing on Waymo’s request for an injunction on Uber’s self-driving program is scheduled for May.

Waymo sued ride services company Uber earlier this year, claiming that former Waymo executive Anthony Levandowski downloaded over 14,000 confidential documents before leaving the company to join Uber. Waymo said Uber benefited from those documents and has sued for damages and to stop Uber from using the technology Levandowski allegedly stole.

Levandowski is one of the most experienced self-driving car engineers in Silicon Valley, and the loss of his expertise would be a major blow to Uber, which has said autonomous vehicles are crucial to future growth.

In court on Wednesday, Uber lawyer Arturo Gonzalez said the company had been working hard to find evidence that Waymo’s documents were in Uber’s possession, but could not find anything material.

Waymo waited several months after learning of the downloads before filing a lawsuit over them, Gonzalez said. He argued the time lag before requesting the documents showed the materials are not crucial enough to merit an injunction in the case.

Waymo’s attorneys argued that Uber has not searched hard enough.

Alsup ordered Uber to conduct a broader search, and said that the weight of Waymo’s evidence “could lead to a preliminary injunction that Levandowski cannot work on this project any more until this case is over.”

Alsup emphasized that he had not yet decided how he would rule.