Google has asked a judge to block Uber’s work on self-driving vehicles. This has escalated a high-profile intellectual property dispute between the two technology companies and added to the growing list of Uber’s troubles.

Waymo, Alphabet’s self-driving car company, filed an injunction on Friday requesting that a judge prevents Uber from using technology that Waymo alleges was stolen.

Last month, Alphabet accused Uber of “calculated theft” of its technology with an explosive lawsuit alleging that a former Waymo employee, Anthony Levandowski, plotted to steal trade secrets before starting a new self-driving truck firm called Otto, which Uber eventually acquired. The complaint centers on Waymo’s proprietary LiDAR system, a technology that self-driving vehicles use to observe the road.

Uber, which considers self-driving vehicles a key part of its future, has benefited from tens of thousands of confidential files and millions of dollars worth of research at Google. This is according to the lawsuit, which now poses a major threat to the ride-sharing company.

The court filings seek to force Uber to return “unlawfully taken” documents and includes testimony from multiple Waymo officials and a former colleague of Levandowski.

Gary Brown, a Waymo security engineer in forensics, wrote in sworn testimony that Levandowski’s laptop downloaded 14,000 files and that two other former Waymo employees who later joined Otto also exported documents. According to the filings, Levandowski stole documents related to calibration, assembly testing and more, while Sameer Kshirsagar, a global supply manager, retrieved documents related to lasers, lens packaging and other areas.

An Uber spokesperson referred back to an earlier statement, saying, “We have reviewed Waymo’s claims and determined them to be a baseless attempt to slow down a competitor and we look forward to vigorously defending against them in court.”

“Competition should be fueled by innovation in the labs and on the roads, not through unlawful actions,” said Waymo spokesperson in a statement. “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.”

The injunction is the latest headache for Uber CEO Travis Kalanick, who was recently forced to apologize over a video that emerged of him berating an Uber driver who questioned him about fares. The executive has also faced intensifying backlash surrounding the company’s reportedly toxic culture.

Kalanick’s brief involvement on Donald Trump’s advisory council earlier this year inspired the viral #DeleteUber campaign.