Paparazzi are reportedly gaining access to the private flight itineraries of celebrities, in what has been described as a security threat to airlines.
The Australian reports the Virgin Australia travel itineraries of Naomi Watts, Rebel Wilson and Nicole Kidman and husband Keith Urban have been accessed.
The itineraries are believed to have been sourced from global booking system Sabre, which is used by Virgin, though a competing system, Armadeus, used by Qantas, is also said to be vulnerable to being hacked.
With exclusive celebrity shots often fetching tens of thousands of dollars, private travel itineraries is an extremely valuable tool for paparazzi.
In a statement, Qantas said the safety of its passengers was paramount.
"If breaches are reported to us, we will immediately act upon them including referring them to the authorities," it said in a statement.