Greyball, a programme that uses data from the Uber app and other technologies, was created to protect the firm from "violations of terms of service" and approved by Uber's legal team, but it also allowed the tech giant to "identify and circumvent" officials who aimed to clamp down on the service, The New York Times originally reported yesterday.
Rides requested from spots near city enforcement agencies suspected of launching stings to trap Uber drivers could be ignored or cancelled, for instance. The technology allowed the firm to show images of "ghost" Uber cars or show that no cars were available in order to swindle authorities.
In some cities that lack a legal framework for ride services, officials have worked to ticket, tow and impound Uber cars.
A spokeswoman for Uber said Greyball was still in use, but it had been scaled back. The technology grew out of work to protect the app from disruption by competitors and to safeguard drivers from abuse. In more rare cases, it was used where there were enforcement stings, she said.
Uber's best-known security researcher and vice president of product and growth Ed Baker announced his resignations yesterday without giving reasons. It's unclear if his stepping down was in connection with Greyball.
This is the latest in a series of headaches for the popular ride-hailing app.
Meanwhile, chief executive Travis Kalanick issued an apology last week saying he needed to "grow up" after a video was published showing the Uber boss in a heated argument with a driver over the app's pay rates.
The billion-dollar startup is also facing serious allegations of sexism in the workplace from a former engineer.