A non-stop Perth-to-London flight operated by Qantas was forced to turn around just two hours into the 17-hour journey because of a disruptive passenger, it was reported on Sunday.
The passenger on the QF9 Boeing 787-9 Dreamliner was reportedly handcuffed, masked, and removed by police after the plane returned to Perth on Saturday night.
Passengers told national broadcaster ABC as they queued for a rescheduled flight on Sunday that the man had been acting strangely and locked himself in the toilet for more than an hour shortly after take-off on one of the world's longest passenger flights.
When he finally emerged, he started shouting at other passengers and squaring off as if for a fistfight.
Passenger Christine Kohli said cabin crew asked passengers for help to try to calm the man.
"They did ask for some assistance from some male passengers, and some passengers went and helped him. I understand he was restrained down the back of the plane."
"I think it was scary for quite a few people, one of the passengers I was with became quite agitated and quite upset, but I think the air crew were marvellous, they were very in control of the situation, they were calming passengers.
"They were very, very supportive. They got him down to the back of the plane quite quickly. It was clear he was quite an unwell man."
Kohli said, despite the delay to her holiday, she was pleased with the actions of the crew.
"I'm grateful for the professionalism and the fact that they put our safety first," Kohli told ABC.
Police said a 32-year-old man was removed from the flight and was being questioned.
Qantas had to reschedule the flight for the next day, as attempting it again on Saturday would have pushed crew members past the time they are allowed to work daily.
Qantas has apologised for the inconvenience to passengers, but said it takes a zero-tolerance approach to disruptive behaviour on board its aircraft.