Cab-hailing service Uber is being investigated by the United States Department of Justice for allegedly using a software tool called Greyball to get around government regulations, Reuters reported on Friday. An unidentified official told The Washington Post that the company has been accused of using the technology in regions where their services are banned or restricted.

Uber’s use of the tool was revealed by a The New York Times report in March. Greyball, among other things, allows Uber to deny rides to specific individuals. While Uber said this was used to penalise riders who had violated their policy guidelines, the New York Times report revealed that Uber also used Greyball to deny rides to government officials who were investigating it for breaking local laws. Uber used the software in Portland and Oregon, though it stopped after the NYT report came out it in March.

This comes at a time when the company is already facing a slew of legal cases and struggling with business challenges. In March, Uber President Jeff Jones resigned from his post as the president. In February, a former Uber employee alleged sexual harassment at workplace in a blog post and accused the company management of inaction. Kalanick was soon after caught on camera fighting with an Uber driver about rate cuts and pay. Adding to Uber’s woes, Alphabet recently sued the company for allegedly “stealing” its designs for autonomous cars.