(WTXF) - The federal Department of Justice has opened an investigation here in Philadelphia related to Uber.
The criminal investigation is focusing on a software known as Greyball.
They're looking into whether the ride-sharing service used the tool keep regulators from tracking them. The Philadelphia Parking Authority says it is cooperating with federal law enforcement.
They're also investigating the software in Portland, Oregon.
Uber has had its share of troubler here.
The PPA, which also oversees Philadelphia's taxis, said in October it would continue enforcing restrictions against unlawful ride-hailing services, including UberX and Lyft. The state legislature's temporary authorization of ride-hailing companies expired at the end of September.
Since then, it settled a dispute with Pennsylvania's Public Utility Commission for $3.5 million for operating in the state without authority for six months in 2014.
But Uber gained popularity in Philadelphia during November's SEPTA strike.