THE Australian Federal Police is investigating 15 unauthorised radio transmissions made with planes over Melbourne and Avalon airports.

The Herald Sun is reporting a mystery person was using a portable radio to give false instructions to incoming aircraft, overriding air traffic control in the tower with planes instructed to go around, resulting in delays.

Authorities say there is no current threat to the safety and security of the travelling public as a result of these radio transmissions, and travellers do not need to change their plans.

The AFP’s head of Crime Operations, Chris Sheehan, said appropriate procedures are in place to ensure the safety of aviation operations in Victoria.

“The AFP, Airservices, the Australian Communications and Media Authority (ACMA) and the aviation industry are all committed to ensuring the safety of the travelling public and we are treating this matter extremely seriously,” he said in a statement.

“These incidents are being thoroughly investigated by the AFP, with technical support from the ACMA. The airlines have been briefed to ensure the advice has been passed on to their pilots and to ensure appropriate measures are in place.”

Unauthorised transmissions on non-public radio channels is an offence, and the person responsible could face up to 20 years in prison.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000.