The Civil Aviation Safety Authority (CASA) is investigating the unauthorised use of a drone during the Supercars weekend in Newcastle.
CASA said it detected the drone flying during last Saturday's RAAF jet demonstration flight and operating above the Supercars track.
"The drone was detected in close proximity to the RAAF FA-18 Hornet aircraft display flight and flying over people at the race," the authority said.
"Drones must never be flown when aircraft are operating as they pose a risk of a mid air collision.
"Drones must never be flown over crowds or groups of people or within 30 metres of a person.
"Using mobile drone surveillance equipment CASA was able to pinpoint the location of the person flying the drone as well as the precise flight path of the drone.
"CASA uses mobile drone surveillance equipment at public events and gatherings to ensure drones do not pose a risk to the community."
Inquiries are continuing to be made by CASA into the incident on November 23 to "gather more evidence to determine if there were serious breaches of the Civil Aviation Safety Regulations".
Breaches of the drone safety rules may include flying a drone in a way that threatens the safety of a person, operating in a way that threatens the safety of an aircraft and endangering a life of a person.
Penalties for breaches of the drone safety rules include fines of up to $10,500 and imprisonment of up to five years.