Fingerprints can reveal within seconds if someone has been taking cocaine, say scientists.

The British technique could pave the way for a simple new test for the illegal class A drug.

Researchers from the University of Surrey developed a way of analysing chemical cocaine traces in fingerprints.

When someone has taken the drug, traces of two “marker” chemicals benzoylecgonine and methylecgonine are excreted from the skin.

Cocaine stock(Steve Parsons/PA)

The chemicals are present in fingerprint residue, and can be detected even when a person is tested after hand washing.

The Surrey team used a chemical analysis method called paper spray mass spectrometry to identify the cocaine markers in fingerprints from patients seeking treatment at drug rehabilitation centres.

It proved to be 99% effective at detecting cocaine use among the patients.

Dr Melanie Bailey, who co-led the study, said: “This is a real breakthrough in our work to bring a real-time, non-invasive drug-testing method to the market that will provide a definitive result in a matter of minutes. We are already working on a 30-second method.

Fingers.(Svand/Getty Images)

“It is non-invasive, hygienic and can’t be faked. By the nature of the test, the identity of the subject and their drug use is all captured within the sample itself.”

The technology could be adopted by law enforcement agencies within the next decade, said the researchers.

The study is reported in the journal Clinical Chemistry.