A domestic flight from Perth was prevented from taking off for almost an hour after a passenger snuck into the toilet and smoked a cigarette.
The Rex Airlines flight bound for Melbourne was delayed for 50 minutes in the early hours of Thursday over the incident.
The Australian Federal Police were called, and the person voluntarily got off the plane about 12.30am, an AFP spokesperson said.
Federal Police are investigating the incident and have confirmed no charges have been laid.