Uber is being investigated by the U.S. Department of Justice for a software that helped its drivers evade law enforcement and transportation regulators, according to Reuters.

The ride-sharing company acknowledged the tool, called 'Greyball', helped it identify and avoid officials who were cracking down on Uber in areas where the ride-sharing service hadn't been licensed such as Portland and Oregon.

Greyball even helped Uber evade authorities overseas in countries such as Australia and China, according to the New York Times.

The program was first brought into the spotlight by a New York Times article in March and was later banned for that use after the report sparked a flood of negative publicity.

Uber said Greyball was created to check ride requests to prevent fraud and for the safety of its drivers.

The ride-sharing company claimed that was the primary use of the program and Uber lawyers said in letters to Portland authorities that Greyball was used "exceedingly sparingly", according to Reuters. 

The technology used by Uber flagged users they saw as a different version of its standard app. The company said the software hid Uber car locations from certain users for security reasons.

The software was part of Uber's Violation of Terms of Service which analyzes credit cards, device identification, location data and other factors to figure out whether a request is legitimate or not.

However, Greyball was also used to identify local officials who could be out to fine drivers or impound cars.

The software even looked into certain credit cards to see if they were from credit unions used by local police and looked into social media profiles for potential law enforcement officials, according to the Reuters report.

Uber received a subpoena from a Northern California grand jury seeking details about when and how Greyball was used. A formal request for documents does indicate a criminal wrongdoing is being investigated, it doesn't mean charges will be brought forward.