Jetstar has apologised after a crew member advised Splendour in the Grass festival goers to dump their drugs before landing in Sydney.
People who attended the music festival near Byron Bay were on a flight out of the Gold Coast on Sunday night when the crew member issued a public announcement.
The flight attendant said sniffer dogs and quarantine officers were waiting at the domestic terminal and advised them to flush "anything you shouldn't have" down the toilet.
The announcement reportedly sparked a rush to the bathrooms.
Jetstar says the staff member will be reprimanded.
The airline says the staffer was complying with a requirement that airlines make quarantine announcements, but the crew member's words were "poorly chosen and plainly at odds with the professional standards we'd expect from our team".
But some took a more positive view.
"Thank you for caring for your Splendour passengers," one person posted on Jetstar Australia's Facebook page. "Very thoughtful and kind thing to do.
"Hope the staff member will be promoted."