Jetstar has said there was no security risk onboard a flight at Sydney Airport after crew onboard requested the attendance of the Australian Federal Police.
The Jetstar JQ501 service due for Melbourne was preparing to take off this morning when the crew became concerned about one passenger's behaviour.
Earlier reports said a fight had broken out onboard, which the airline refuted.
A Jetstar spokesperson said the AFP were requested by crew after a passenger's behaviour was deemed to be unusual.
"Our crew noticed a passenger behaving unusually and requested AFP attendance," the spokesperson said.
"The aircraft returned to the gate and the passenger chose not to fly. We now understand the customer was a nervous flyer and was experiencing anxiety.
"We also understand the situation made some other people onboard feel uneasy and they also decided not to continue with their journey.
"As a result of this we had to delay the flight and apologise to customers for the inconvenience."
Earlier, a passenger named Sharee told Today that multiple people asked to get off the plane following the ordeal.
Sharee said six passengers asked to leave to plane, after feeling "a bit nervous".
"We were already on the runway and an announcement was made that due to operational issues we will have to return back to the gate and we did," she told Today.
"We saw a crew member talking to a passenger and the passenger, yelled out, 'This is ridiculous. There's a war going on in Palestine'.
"The crew member said to him, 'He's welcome to leave the flight' and he got up and was getting his bags to leave."
Sharee said it was a concerning experience, but said the staff handled it well.
"They were very open to answering everybody's questions," she said.
"We were told the original reason (why) we were turned back was another passenger was not happy with their seat.
"Crew members tried to explain to them that they could change seats after we took off but they insisted they want took off but they insisted they want to leave the plane."
Passengers have been re-booked onto Jetstar flights that will arrive in Melbourne today.