Waymo, the Alphabet subsidiary that took over Google's self-driving car project, alleged last month that Uber stole its technology. Now it wants a court to force Uber to suspend its own self-driving research.

Waymo's lawyers filed several new documents on Friday in the company's case against Uber and formally asked the judge to block Uber from operating its autonomous vehicles, The Verge reports. Waymo's lawsuit alleges that former Google engineer Anthony Levandowski downloaded more than 14,000 proprietary design files—9.7GB worth of data—for a LiDAR system in late 2015 before he left the company to found Otto, which Uber later acquired.

Among Friday's filings are engineer testimonies that appear to bolster Waymo's claim that Otto's LiDAR systems were stolen from Google. One Google forensic engineer offered sworn testimony that Levandowski downloaded the files to his personal laptop, and another engineer recalled Levandowski telling her before he left Google that he wanted to start his own self-driving car company using the existing LiDAR designs, according to The Verge.

Based on that testimony, Waymo said, Uber should be required to shut down the parts of its research that use the LiDAR designs.

"Given the strong evidence we have, we are asking the court step in to protect intellectual property developed by our engineers over thousands of hours and to prevent any use of that stolen IP," a Waymo spokesperson told The Verge.

Uber did not immediately respond to a request for comment on Friday's filings. In a statement after the lawsuit was filed in late February, the company described the claims as baseless and said that it would "look forward to vigorously defending against them in court."

Uber self-driving taxis are currently on the road in Pittsburgh and Tempe, Arizona. The company is also trying to secure a permit in California after being kicked out of San Francisco for launching there without one.