Here's the DOJ's letter that delayed the Waymo-Uber trial

In a letter to the judge overseeing Waymo's lawsuit against Uber, the Justice Department says that a former Uber employee suspected the company helped its then-CEO covertly communicate with a startup the company eventually acquired. A document detailing the employee's original concerns will be released on Friday.

Why it matters: The Justice Department's notice to the court led to a second delay to the trial between the two companies. The ex-Uber employee's concerns, which he communicated to the company back in May after being fired, were never mentioned in the case until that point, raising questions about whether the ride-hailing company was purposefully hiding.

• This is also the first confirmation of a Justice Department criminal probe into Uber, beyond rumors and media reports.

However: Another Uber employee testified last month in court that the presentation he gave on secretive communications, referenced by the former employee and Justice Department, was purely hypothetical. In fact, he and his team had no idea that Kalanick and the startup's founder communicated without leaving a trace until Bloomberg published an article detailing their tactics months later. Uber also argued in court that the former employee sought to extort money from the company after getting fired for poor performance.

Note: The case was referred in May to the U.S. Attorney's Office for a potential criminal probe.

Here's the full Justice Department letter: