Chicago police said on Tuesday they are investigating an allegation that a driver for the online car service Uber raped a female customer.
Chicago police said in a statement that they have been in contact with the woman as well as Uber personnel, but declined to give further details.
Uber spokeswoman Jennifer Mullin called the incident "appalling and unacceptable." She said the company immediately removed the driver from the Uber platform when it learned of the incident, and is cooperating with police in the investigation.
Mullin said that all drivers with the ridesharing service undergo a "rigorous background check." Uber is one of several ride-sharing services gaining popularity in cities, despite opposition from taxi companies that typically operate under stricter regulations.
The Chicago investigation comes as Uber has been in the news for other issues with government authorities. Also on Tuesday, California prosecutors said that a former Uber driver was charged with misdemeanor vehicular manslaughter in the death of a 6-year-old girl who was struck in a San Francisco crosswalk on New Year's Eve.
On Monday, Portland, Oregon sued Uber to stop the service from operating in the city until it follows local regulations. The same day, the company was banned from operating in India's capital, New Delhi, after a female passenger accused one of its drivers of rape.
The fast-growing company was valued at $40 billion last week after its latest funding round ahead of an expected initial public offering.