An Indian-origin science student in the UK has devised a novel way to locate tiny, previously undetected traces of cocaine on surfaces.
The research, carried out at the University of Derby using a new method of forensic analysis, may help police find minute traces of drugs.
Sonica Devi, 22, a final year student at the university, tested her method on samples taken from telephone boxes across Derby.
The university said she used an ultra sensitive Gas Chromatographic technique, which allowed her to find cocaine at picogram levels - one million millionth of a gram - from forensic swabs.
Gas Chromatography linked to a mass spectrometer (GCMS) is an established technique for separating complex mixtures of compounds and detecting them down to very low amounts.
The new breakthrough makes detection of the drug possible even at a million millionth of a gram.
A picogram is one thousand times smaller than a nanogram and a thousand thousandth times smaller than a microgram (a millionth of a gram).
"I had no idea what I would find through this study as no trace of drugs could be seen in the phone booths with the naked eye - I was surprised at what the research found," the Telegraph quoted her as saying.
"I am keen to take this research forward and would be keen to work with other agencies or organisations to develop this further," she added.
The study is now being presented at a number of forensic science conferences across the UK.