Scientists have devised a new way to check someone’s fingerprints and tell within seconds whether they’ve used cocaine.

Led by the University of Surrey, the study was published in Clinical Chemistry. It is the first large-scale study of cocaine users, and could lead to a breakthrough in how Class A substances are detected.

The research, conducted in tandem with the Netherlands Forensic Institute, used something known as paper spray mass spectrometry. Fingerprint samples were detected on chromatography paper, which can separate substances, and then treated with chemicals to bring out the definition of the fingerprint and identify the individual.

When someone had taken cocaine, the fingerprint retained some key chemical indicators, benzoylecgonine and methylecgonine, even after the participants had washed their hands.

In the study, 239 fingerprint samples were used. Incredibly, the team had a 99 percent success rate in identifying cocaine use, with a 2.5 percent false-positive rate. Obviously that’s not perfect – but it’s pretty darn impressive.

During the study, it took about four minutes per sample to find out if the person had used cocaine or not. However, the team said this could be reduced dramatically in the future to make the test quick and efficient.

“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,” Dr Melanie Bailey, one of the study’s co-authors, said in a statement.

The test is seen as being particularly good because it is hygienic, non-invasive, and it cannot be faked. The technology in the study could be used by police within a decade.

According to the National Statistics Office, about 2.7 million people aged 16 to 59 (one in 12 adults) took illicit drugs in 2015 and 2016 in England and Wales. More than 8,500 people (England) were admitted to the hospital with drug-related mental health and behavioral disorders, and there were 2,500 deaths (England and Wales) from drug misuse in 2015.