Footage of the aircraft, heading to Ballina in northern New South Wales, on social media shows the door beyond the jet’s right side wing still open while moving slowly on the runway.
The Qantas Group-owned carrier said it was currently investigating the incident and working with its ground handler to prevent a recurrence.
“A rear cargo door was left open after the door was unlocked to add a piece of oversized luggage to the hold at Sydney airport on Tuesday morning,” Stuff reported, citing a statement from the airline.
“After the aircraft pushed back for departure, our pilots received a notification that the cargo door was open and returned to the bay,” the company said.
“There was no safety risk at any stage; multiple system safeguards ensure an aircraft cannot take off with a cargo door open.”
The flight departed later on Tuesday for Ballina.