More than one in every ten UK banknotes in circulation is tainted with cocaine powder, new research suggests.
UK police say growing use of the class A drug means the number of notes carrying traces of it has trebled in six years.
Worryingly, specialist drugs officers say cocaine taken in combination with alcohol is fuelling violence on Britain's streets.
Yesterday, one warned that Labour's 24-hour drinking laws had sparked a rise in cocaine use - as it is often taken by drinkers who want to stay out all night.
Details of the growing prevalence of cocaine were given to a meeting of the Government's official drugs body yesterday. Pc Adrian Parsons, Kent Police's drug expert evidence coordinator, told the Advisory Council on the Misuse of Drugs that users were taking 'coke' so they could carry on drinking into the early hours.
He said: 'It's my personal view that the change in licensing laws led to a rise in the use of cocaine.
'We have got extended licensing hours, we have got people who are not ramming as much down their necks as before 11pm and who are going all night.
'Cocaine is everywhere, it's a drug we see all over the place.'
Kent constabulary, along with ten other forces, routinely tests banknotes - which are often rolled up by users to 'snort' lines of the drug - seized during raids. Up to 70 per cent taken from suspected drug dealers have cocaine traces.
But the programme has also tested 5,000 ordinary notes and found startling rises in positive cocaine tests in recent years.
Six years ago, around 4 per cent of notes showed cocaine residue from a simple swab test. But the most recent figures show that has nearly trebled to 11 per cent.
Tests have also shown rising evidence cocaine is being mixed with MDMA, the active ingredient in dance drug ecstasy.
Users are unaware they are taking a drug cocktail.
Pc Parsons pointed to figures from Liverpool John Moores University that showed before the 2003 Licensing Act - which let pubs stay open after 11pm from November 2005 - most users took the drug for 'social confidence'.
But recently the same study, of 17- to 29-year-olds, has shown the reason given most often is to 'keep going and stay awake'.
Around one in 11 adults in England and Wales admits having taken cocaine. Pc Parsons said cocaine and alcohol in combination led to users having an 'air of invincibility', and made them more likely to be aggressive towards the police.
Other evidence showed use was highest among higher earners, and users in England are most likely to be aged 20 to 24.
Figures from Drugscope show cocaine cost £70 a gram in 2003 but is now as little as £40 a gram.
Drug experts warn the addictive substance can lead to heart attacks, strokes and brain seizures.