She was travelling alone and didn't talk much with other passengers.

They only noticed she was not moving after the pilot asked passengers to prepare for descent. She didn't wear her seat belt and one of the hosteses' walk up to her and notice she was turning blue.

An Australian woman died on an international flight across the pacific. The plane was headed to Pertg in the country's western region after it took off from Los Angeles.

The 42-year old, whose identity has not been announced, is suspected to have swallowed some banned substances including cocaine.

Emergency services were called to Sydney International Airport on Thursday while police officials boarded the plane and established a crime scene.

Passengers were left waiting on the tarmac for over 90 minutes while evidence was being gathered.

Local 2GB Radio reports that there are suspicions that the woman might have been a drug vessle but New South Wales police declined to comment on the claim.

Police say they are investigating possible causes of death including self-harm or natural circumstances.