Reports of anti-social behaviour in Norfolk market towns rose by as much as 23pc in the last 12 months, contrasting with the declining trend across the county as a whole.

Norfolk Constabulary was praised by government inspectors last week for its efforts in tackling the problem with above-average responses to a survey about their handling of calls.

Those findings are endorsed by county-wide figures which show ASB in the past year has dropped from 63,256 to 55,295 incidents.

But that trend is being bucked by towns like Dereham, Thetford, Swaffham and Fakenham, which have seen reports rise by between 12pc and 23pc.

The statistics on Norfolk police's crime-mapping website are based on a rolling three-month average, compared to the same period in 2009.

The trend is not universally repeated, with Cromer's figures showing a 39pc decrease, and central urban areas of Norwich, King's Lynn and Great Yarmouth seeing a fall in line with the county average.

Senior officers put the phenomenon down to the success of partnership initiatives which have boosted public confidence, leading to a rise in reports.

Supt Mike Fawcett said a good example was a pilot scheme in Breckland, where a police sergeant is stationed at the district council offices with a computer terminal to give officials up-to-the-minute data on developing problems.

He said: 'Dereham, Fakenham and Thetford and other market towns have seen ASB figures rise, and we believe this is due to proactive reporting from residents, following on from actions such as the experimental pilot scheme in Dereham where our officers are working closely with council partners to encourage people to report issues to us, and other schemes, such as reporting of issues near public houses.

'We welcome anything that encourages residents to proactively contact us and let us know what is happening in their area so that we can work to resolve matters raised as a concern.'

Despite a 23pc rise in reported ASB in Dereham, neighbourhood police and town councillors said they had not noticed a worsening problem.

But they agreed there was more awareness – particularly after the massive success of a campaign in the Charles Close area of Toftwood last year, which reduced reported ASB incidents from one per day to one per month.

Robin Goreham, a town and district councillor for Dereham, said: 'From a councillor's point of view it is a matter for concern when any crime figures go up.

'But I have not had any complaints for some time about ASB in Dereham Central. All I can think of is the perennial problem of youngsters gathering on street corners with nothing better to do. That can lead to ASB, but I am puzzled as to where it has gone up by 23pc.'

Sgt Mark Goodbody, said Dereham's Safer Neighbourhood Team had expanded since last year's force reorganisation, and that officers would continue to work through priorities agreed with the local Community Action Group – which currently include ASB in the Lynn Hill area and around Dereham Golf Club.

'This is due to more proactive reporting,' he said. 'You never get a true idea of the scale of a problem unless people report it faithfully, and the message is getting across that, if people report it, then something will be done about it.'