The city of Portland, Oregon, is starting its own investigation of Uber Technologies Inc.’s use of software to evade regulators while a U.S. Justice Department criminal probe continues in that city along with Philadelphia and Austin, Texas, according to officials. The Portland City Council voted Wednesday to subpoena San Francisco-based Uber seeking information about the so-called Greyball program that wasn’t provided by the ride-hailing company in an earlier audit by the city’s transportation department. Uber said in March it was ending the practice of showing fake versions of its app to government officials suspected of conducting sting operations on drivers. The program blocks users who the company believes are in violation of its terms of service agreement. In the past, that has included government officials and enforcement authorities in cities who request rides with the intent of ticketing drivers or impounding cars in areas where Uber may not be authorized to operate. The system would cancel rides or display cars that weren’t actually nearby. The U.S. attorney’s office in San Francisco, which Portland has said is leading the federal investigation, has declined to comment on it. Portland launched its Greyball audit in March after the New York Times first reported on the program. City attorney Tracy Reeve said her office plans to issue a subpoena this week after the company declined to share what city documents describe as a “playbook” of tactics “used to deceive local regulators and block riders within a given city.” An Uber representative didn’t immediately respond to a request for comment. Officials in Philadelphia and Austin said Wednesday said the cities are cooperating with the Justice Department investigation.