In the battle between ride-hailing apps, Lyft is the clear underdog, with a smaller share of the market and a lower valuation. However, it turns out the company may have used a pretty dirty tactic against the more dominant Uber.

Reuters reports that the Department of Justice (DOJ) is investigating a breach at Uber that revealed the license plate numbers and names of up to 50,000 of its drivers. According to two anonymous sources, the attack can be traced back to an IP address allegedly associated with Lyft's technology chief, Chris Lambert.

Lambert actually hired a lawyer recently, but claims that move has "nothing to do" with Uber. The DOJ wouldn't confirm or deny the investigation, though Lyft says it hasn't officially been accused of committing any crimes.

"Given that Uber apparently lost driver data, a law enforcement investigation is to be expected," Lambert's lawyer Miles Ehrlich told Reuters. "And the benefit is that the culprit here is going to be identified, and that's going to remove Chris' name from any conversation about Uber's data breach, as it should."

If it turns out that Lyft was behind the breach, it could spell bad news for the company. The two firms have never exactly gotten along, and we doubt Uber will go easy on its competitor in court if it has the chance.

Update: An earlier version of this article incorrectly suggested that Uber had accused Lambert of the breach directly. We also received the following statement from Lyft on the matter:

We have not been contacted by the DOJ, U.S. Attorney's office or any other state or federal government agency regarding any investigation.

Our investigation into this matter was thorough, and there is no evidence that any Lyft employee, including Chris, downloaded the Uber driver information or database, or had anything to do with Uber's May 2014 data breach.