The Federal Aviation Administration, the United States' nodal agency on civil aviation, has said it was investigating a viral internet video created by an 18-year-old student Austin Haughwout, displaying a homemade "drone" firing a handgun in the Connecticut countryside.
The 14-second video called "Flying Gun", which has been viewed nearly two million times, has sparked fresh debate about the still largely unregulated world of civilian drones in the United States.
The footage shows a homemade multi-rotor hovering off the ground, buzzing furiously and firing a semiautomatic handgun four times at an unseen target.
Watch: The gun-mounted drone firing into a distance
It was posted on YouTube on July 10. The device was created by Austin Haughwout, a mechanical engineering student from Clinton, Connecticut.
"The FAA will investigate the operation of an unmanned aircraft system in a Connecticut park to determine if any Federal Aviation Regulations were violated," it said in a statement.
"The FAA will also work with its law enforcement partners to determine if there were any violations of criminal statutes."
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 AFP by telephone.
"The proper name for this is an RC quadcopter. The media keeps using the inappropriate word because it helps you to generate fear," he added.
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."