A wrap of cocaine can cost just £25
Evidence has emerged which points to a link between cocaine use and violent behaviour in Britain's city centres.
Figures from Greater Manchester Police suggest that 41% of people arrested for violence had taken cocaine or crack cocaine, by itself or with other drugs.
The force took samples from 1,000 people arrested for offences such as assault, wounding and affray in the seven months to March last year.
The charity DrugScope revealed the results in its magazine, DrugLink.
The survey was part of an article which considered whether mixing alcohol and cocaine was a recipe for disaster.
Similar findings had been reported in the Liverpool area after a separate study, run last summer by John Moores University.
Chief Inspector Dave Boon, who leads Greater Manchester Police's drug intervention programme, said while only a small number of offenders had been tested so far, the statistics were important.
"We cannot afford to ignore the link between violence, drugs and alcohol that is apparent in city centres all over the UK every weekend," he said.
"What this survey is doing is trying to prove that link and developing ways to manage the problem."
DrugScope chief executive Martin Barnes said: "The investigation carried out by our magazine does suggest some link between powder cocaine use and violent and aggressive behaviour.
"However, because the drug is so often taken in combination with alcohol we need to be cautious about claims that cocaine alone can lead to violent offending."
Cocaine is more widely used in Britain than ever, while the average price has halved in a decade. A wrap can cost as little as £25.
Further research will be conducted this year, with police keen to establish whether there is a link between alcohol, cocaine and domestic violence.