A critically ill passenger died during a Qantas flight from London to Sydney in the early hours of Friday morning.
A Qantas spokesperson confirmed that the female passenger, who received treatment from medics and cabin crew including CPR, has died.
The flight made an emergency landing in Adelaide at about 3:50am due to the incident, and departed again for Sydney at 6am.
Another passenger told news.com.au that an announcement over the speaker at about 3am asked for medics to come forward. A doctor and others with medical training began helping the woman with the assistance of the flight crew.
"The crew did everything they could, including helping perform CPR with a doctor who was on board, but unfortunately the passenger has passed away," the Qantas spokesperson said.
The spokesperson did not provide any further details out of respect to the woman's family.
South Australian Police said in a statement that the death was not being treated as suspicious, and a report would be prepared to the coroner.
It said the plane was diverted to Adelaide after her death.