Turnbull wrote in a 1994 book "The Reluctant Republic" that it was "difficult to believe that Prince Charles could ever be accepted as king".
A reporter for the Hit105 radio station asked, "Is it true that you, uh, carry your own toilet seat when you travel?".
Prince Charles used a ideal choice of words to dispel an ongoing toilet-related rumour.
It will be the final day the prince and duchess are together, with Camilla set to attend events in Brisbane on Friday before flying home, while Charles will fly to Bundaberg and then on the Vanuatu, Cairns and Darwin.
The exposé, written by British investigative writer Tom Bower, is titled the Rebel Prince: The Power, Passion and Defiance of Prince Charles, make ludicrous claims like Charles sending multiple bedrooms' worth of furniture before of an overnight visit to a friend, including his own bottled water and toilet seat.
Expert doesn't expect new Rohingya boat people exodus
Malaysia's standard policy has been to turn away refugee boats attempting to make landfall, unless weather conditions are bad. In the video, Abu tells the interviewer; "We are moving because during the monsoons, the water rises very high here".
Pochettino on Harry Kane's fitness, Daniel Levy's earnings and Stoke clash
Stoke are second from bottom with 27 points from 32 games and face an uphill task to ensure their survival. Tottenham coach Mauricio Pochettino took questions from the media ahead of their trip to Stoke .
Kim Kardashian shares first-ever photograph of her new family-of-five
Kardashian recently opened up about ET about how her older kids are with baby Chicago , whom the family welcomed via surrogate in January.
And while he was there he was quizzed on claims made in a new biography that Charles carries his own toilet seat everywhere he goes.
We've listened to the audio several times, and have decided that the Duchess' wordless response is the exact midpoint between an embarrassed groan and an annoyed sigh.
The tour comes as Australia is debating having a local head-of-state after the death of Queen Elizabeth.
Charles was greeted in Brisbane by Governor-General Peter Cosgrove, a former Australian army general who represents the monarch in Australia, and was welcomed with a 21-gun salute.
Games organisers insisted that the duchess was not bored by the three-hour opening ceremony after it left her "shattered" and needing "to go to sleep".