A viral online video apparently showing a home-made drone firing a handgun in the US is being investigated by the Federal Aviation Administration (FAA).
The announcement came on Tuesday, after the video had been watched more than two million times since being uploaded to YouTube on July 10.
"The FAA will investigate the operation of an unmanned aircraft system in a Connecticut park to determine if any Federal Aviation Regulations were violated," the administration said in a statement.
"The FAA will also work with its law enforcement partners to determine if there were any violations of criminal statutes."
The 14-second video, called "Flying Gun", shows a multi-rotor drone hovering off the ground, buzzing furiously and firing a semi-automatic handgun four times at an unseen target in the countryside.
The device was reportedly created by 18-year-old Austin Haughwout, a university mechanical engineering student from Clinton, Connecticut.
Not a drone
Haughwout's father, Bret Haughwout, denied his son had built a drone.
"People have been playing with RC [remote-controlled] toys for many decades," he told the AFP news agency.
"The proper name for this is an RC quadcopter. The media keeps using the inappropriate word because it helps you to generate fear."
Haughwout said the FAA had not been in touch.
"I don't understand why people are making such a big deal of it. It's not like it's anything new," he said. "He's a mechanical engineering student. He builds all different kind of things."
The video has sparked fresh debate about the still largely unregulated world of civilian drones in the US.
The FAA has a September deadline for a final set of rules to govern civilian drones in crowded US skies, but it is expected to miss it.
The industry argues that strict regulation would mean the US will fall behind other countries in developing high-value drone technology.
In Switzerland, the postal service has begun testing parcel deliveries by drones. In the Indonesian capital, police deployed them for the first time this year to monitor traffic.