News that Uber used a secret program to tip the scales against city regulators in 2014 has not sat well with city officials.

Three days after the New York Times reported on a tool called "Greyball"—which, in part, could identify likely city regulators, ensure they weren't given rides, and show them nonexistent Uber drivers buzzing around the in-app map—Mayor Ted Wheeler and Transportation Commissioner Dan Saltzman this afternoon announced the launch of a city investigation into the practice.

Wheeler also strongly hinted that the state Department of Justice or other entities could be brought in to ferret out the practice, which Uber told the Oregonian hasn't been used here since 2014, after the city and the company stopped a fast-mounting legal battle and agreed to begin a process where Uber and its competitor Lyft might operate legally in Portland.

"This is a company that has taken the time at the highest levels to create a special application for the purpose of falsifying information on their primary app for regulators," Wheeler said this afternoon. "We now have an affirmative obligation to unearth those facts."

The scope of the city's investigation, and the potential fallout, isn't completely clear. Saltzman vowed that the Portland Bureau of Transportation (PBOT) would "review all of our compliance audits, rider complaints, and any other data we may need from the companies to reach a determination" into whether Greyball was used after the city and Uber reached an agreement.

He also voiced confidence the city had the ability to unearth records under a groundbreaking data-sharing agreement the city reached with Uber in 2015. That agreement, in part, says Uber will routinely share data about "any unique unfulfilled trip requests," which might get to some of the city's concerns, though PBOT's been routinely shown those numbers.

"We believe the data we have is sufficient to go back and audit," PBOT Director Leah Treat said.

PBOT has characterized Uber as willingly complying with city regulations in recent years, and says there is no indication that the company has been selectively denying service to regulators or anyone else.

Should that change, though, it isn't 100 percent clear on what the penalty would be.

When the city crafted temporary rules for Uber and Lyft at the beginning of 2015, Saltzman said, "it was very clearly spelled out that they cannot engage in any kind of software applications designed to thwart the ability to regulate them. It’s not as clear in our final regulations."

Officials noted, though, that city rules mandate that so-called transportation network companies (TNCs) like Uber and Lyft accept "any request for TNC Service received from any location within the City." Cherry-picking users to be left out would fly in the face of that requirement.

"You cannot deny service to anyone regardless of race, age, ability, geographic location—anything," said Treat.

Saltzman said the PBOT investigation would be complete in 30 days, and shrugged off a question about his relationship with Mark Wiener, a local consultant who's helped with Saltzman's campaigns, and also acted as a lobbyist for Uber. That history does not make Saltzman unfit to oversee an investigation into Uber, he said.

Wheeler strongly suggested other agencies could launch their own inquiries.

"I reserve the right to bring other parties into this on behalf of the city council," he said. "I’m not yet convinced nor have I seen any evidence to suggest to me that we have anything close to the facts. I don’t know whether local laws or state laws were potentially violated.

Asked if he'd request the Oregon Department of Justice to step in, the mayor said "I wonder if I'll actually have to make the call."

Kristina Edmunson, a spokesperson for Attorney General Ellen Rosenblum, says the DOJ is still looking into the matter.

"We have not been asked to investigate (for criminal or civil charges)," she says. "We are looking into the issue, and determining what, if any, jurisdiction we may have."

Adding to the city's ire over the NYT revelations are Uber's efforts at the state level to dismantle Portland's regulatory requirements. A bill the company is pushing in the current legislative session would create statewide regulations for TNCs, and render moot any rules passed by cities. The legislation, House Bill 3246, is currently before the House Business and Labor Committee, and has not been scheduled for a hearing.