The US Department of Justice (DoJ) has launched a criminal investigation into Uber's use of software which helped its drivers track and avoid local transport regulators, it has been reported.
Uber has already come under fire for the secret technology, which used data from Uber to help drivers to "identify and circumvent" transportation officials launching stings to trap Uber drivers.
In a letter written to Ken McGair, deputy city attorney in Portland, Oregon, last month, Uber confirmed the existence of Greyball and said it was designed to protect drivers from users who had violated its terms of service, for example by making physical threats. It added it had used the technology "exceedingly sparingly".
In its report today, Reuters said the DoJ's investigation is still in its early stages. Uber did not comment.
This is the latest in a string of woes for Uber. The company, which is at loggerheads with traditional taxi drivers in almost every country it operates in, has been criticised over its treatment of drivers, and has been at the centre of a sexism scandal.
In March the company closed its operation in Denmark, blaming new regulations which capped the number of licences issued to drivers and forced drivers to fit a taxi meter.
Meanwhile, in February the company faced allegations of sexism after a former engineer published a blog post in which she described being propositioned by a male manager and faced discrimination from its HR team.
During the same month, chief executive Travis Kalanick was forced to apologise after he was filmed having an argument with one of the company's drivers.
“This is the first time I’ve been willing to admit that I need leadership help and I intend to get it,” he wrote.
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