A judge has hit the brakes on the Waymo trial against Uber that was set to begin Dec. 4 after new evidence has surfaced. A 37-page letter from a former Uber employee alleged the ride-sharing company had a team set up to steal trade secrets, the Wall Street Journal reports.

The claims were previously sent to Uber in early 2017 from a lawyer representing Ric Jacobs, a former member of Uber’s security team, and were brought to light Tuesday when the judge overseeing the Waymo/Uber case reviewed the new evidence.

Waymo previously accused Uber's self-driving company Otto of stealing autonomous car technology and is seeking over $1B in damages. Federal prosecutors have since said they are reviewing allegations of theft of trade secrets.

The federal judge has delayed the trial indefinitely to allow for Waymo’s attorneys to review the new evidence. The judge accused Uber’s lawyers of withholding evidence and will hold evidentiary hearings to look at the letter’s allegations further.

The letter describes a secretive culture, devices that kept information stored outside of Uber’s servers and training for employees to avoid regulatory scrutiny. Jacobs left the company in April and later settled with the company on these claims.

Uber’s lawyers said the new testimony should not change the merits of the case with Waymo as the former employee did not testify that Uber stole from Waymo.

Uber Vice President and Associate General Counsel Angela Padilla said the accusations from the former employee were false and part of a plot to extort Uber. The lawyer said the company gets letters with wild accusations from former employees all the time that are never substantiated, but the lawyer was unable to clearly explain to a judge Wednesday why the company paid millions to the former employee as a consultant, the San Francisco Chronicle reports.

The judge later conceded the possibility the letter could be from a disgruntled employee, and Padilla said the letter should have been shared as part of the Waymo trial earlier.