A ten-minute saliva test for cancer that scientists claim could revolutionise diagnosis has been unveiled.

The €20 "liquid biopsy" test looks for fragments of genetic material in a tiny drop of saliva.

Early results from lung cancer patients suggest it has "near-perfect" accuracy, according to the scientist whose team developed the system.

Professor David Wong of the University of California at Los Angeles, said: "We need less than one drop of saliva and we can turn the test around in ten minutes. It can be done in a doctor's office while you wait.

"Early detection is crucial. Any time you gain in finding out that someone has a life-threatening cancer, the sooner the better. With this capability, it can be implemented by the patient themselves in a home check, or dentist or pharmacy."

He hoped the test, due to be tested in trials with lung cancer patients in China later this year, could be available in Europe by the end of the decade.

Eventually it could be used to diagnose a range of different cancers, said Prof Wong, speaking at the annual meeting of the American Association for the Advancement of Science (AAAS) in Washington DC.

The team came up with the test after discovering that saliva contained fragments of the genetic messenger molecule RNA linked to cancer.

"Down the road it might be possible to test for multiple cancers at the same time," said Prof Wong.