COCAINE use in parts of Teesside is higher than in cities such as Amsterdam and London, academics found.

The research, carried out by Teesside University, tested domestic wastewater in both Stockton and central Middlesbrough, and found high levels of the Class A drug.

Stockton's levels of cocaine traces in waste water was the highest, above London and Amsterdam, if the university's figures are compared against data from the European Monitoring Centre for Drugs and Drug Addiction for weekday use.

Middlesbrough's levels came next, above Antwerp in Belgium, Zurich in Switzerland and Barcelona, in Spain.

Academics at the university worked with Northumbrian Water to collect the samples from waste treatment plants at Portrack in Stockton, and in central Middlesbrough, last August.

If the results are checked against data from Europe, they show that cocaine use is higher, but Dr Gillian Taylor, senior lecturer in forensics and analytical science at Teesside University, said it was hard to compare like-for-like because of different variables involved in different tests.

But it showed that cocaine use was almost three times higher at weekends in Stockton, and more sustained throughout the week in Middlesbrough, highlighting different trends in drug use.

Dr Taylor said: "These kind of tests could prove useful in knowing where to deliver targeted drug treatment services.

"For example, dealing with recreational weekend drug use is significantly different from treating sustained drug use.

"The problem with written surveys is that you are relying on drug addicts telling you the truth about their drug use. This could give us a much more reliable picture of how widespread use is of certain drugs."

She said that the research, part-funded by Glaxo Wellcome Trust, would look at heroin and cannabis use next, as these drugs had already been detected in the waste water tested.

Cleveland Police said it was aware of the findings. A spokeswoman said: "Officers in our community drugs enforcement team are aware of the research and will take an interest in the findings as and when it is finalised."

Drug use in Stockton ranged from 379mg of cocaine per 1,000 people on weekdays, peaking at 1,307mg on Fridays, while in Middlesbrough the use was more consistent, between 508mg and 707mg per 1,000 people.

The wastewater is treated by Northumbrian Water before being discharged into rivers and estuaries, where it is heavily diluted and is in such tiny amounts it presents no risk to health, the company said.