For days, a few security experts on social media were buzzing about a mysterious government surveillance SUV in Philadelphia that appeared to be disguised as a Google Street View Car.

A University of Pennsylvania professor tweeted a picture of the suspicious vehicle, which he found parked in the Philadelphia Convention Center’s tunnel Wednesday morning. Motherboard reported Thursday that a placard displayed on the dashboard indicated that the car was registered as a city government vehicle. The SUV is mounted by two license plate reader cameras.

Google said it did not own the vehicle. So did the Pennsylvania State Police.

On Thursday, the Philadelphia Police Department admitted to Motherboard that the SUV is one of its vehicles. But not all of the questions surrounding the surveillance SUV are solved. They told The Washington Post that the department said it did not know who put the Google Maps decal on the vehicle and that the placement of the decal was not approved through any chain of command. It added that it would launch an internal investigation to find out who is responsible for placing the sticker.

The Philadelphia Police Department, which operates separately from the Pennsylvania State Police, has been using license plate reading technology since 2011. These powerful cameras allow law enforcement to track the whereabouts of any Philadelphia resident without a warrant. This data can be stored up to one year for any citizen and indefinitely for anyone who may be linked to a criminal investigation. The license plate storage program is managed by a separate police task force, the Southeastern Pennsylvania Regional Task Force, whose mission appears to include reducing terrorist threats.

Google has told Motherboard that it is looking into how its stickers got on a city police SUV. Why the Philadelphia Police Department would want to disguise this vehicle when it has been openly collecting license plate information is unknown.

But now, at least, several people are asking that question.