(CNN) Police in Australia have launched an investigation after pilots on approach into the Melbourne area received fake air traffic control communications.

The major security breach has seen a hoaxer interfering with incoming passenger flights at Melbourne Airport, in Tullamarine, and Avalon Airport, in Avalon, on at least 15 occasions, the Australian Federal Police (AFP) said in a statement.

"As a result of the unlawful interference with air traffic control broadcasts over several weeks, the AFP has today issued a call for public help for any information that will result in the identification and arrest of the person responsible."

Authorities now believe that the unknown individual has been using a portable transmitter from nearby airport car parks to target incoming passenger flights, according to CNN affiliate 7 News.

Repeated security breaches

On several occasions, the hoaxer contacted planes making their final approach, pretending to be from the control tower.

The unauthorized radio transmissions would force pilots to abort landings and perform a "go around" (an emergency maneuver) instead.

ABC News, a local media service, reported one incident where flight data viewed on FlightRadar24 shows the plane was within 275 feet of the runway at Melbourne Airport before the plane began climbing again.

Airservices, Australia's air navigation service provider, said that no passenger safety was compromised on any of the flights as a result of the fake radio calls to pilots.

The AFP added that while incredibly serious, travelers should not be concerned about their safety and security while visiting the Melbourne area.

"The airlines have been briefed to ensure the advice has been passed on to their pilots and to ensure appropriate measures are in place," said Chris Sheehan, the AFP's acting assistant commissioner.

Australian police have yet to make any arrests but warn that those responsible for the hoax calls face up to 20 years of imprisonment and urge anyone with information to come forward.