Hertfordshire people are “likely” to be losing more than £15million a year at the hands of rogue traders, according to a report by trading standards officers.

Rogue traders often arrive on the doorstep of elderly or vulnerable residents offering to do roofing, building, gardening or driveway works.

But they then charge excessive amounts for the work, that can also be of poor or questionable quality.

In one recent case, according to the report by trading standards, one rogue trader was prosecuted for charging a Hertfordshire resident £69,000 for work on an extension that was independently valued at £17,000.

And another was prosecuted for fraud, acquiring criminal property and engaging in aggressive commercial practice, after taking £28,000 from a bereaved resident, who had initially contracted them to fix a minor leak.

Last year there were more than 50 reports of rogue traders made to the county council’s trading standards officers – and a further 308 reports made to Hertfordshire Police.

But trading standards officers believe there are high rates of under-reporting of this crime – with estimates that as few as five per cent of incidents being reported at all.

And in a report to the council’s Community Safety and Waste Management Cabinet Panel on Friday (November 9), they say that “it is likely that Hertfordshire residents are currently losing a minimum of £15,000,000 a year to rogue trading”.

As part of the measures to combat doorstep crime, the report highlights there are now 169 ‘no cold calling areas’ – covering 9,009 properties – in crime hot spots around the county.

And – with larger incidents often involving victims withdrawing money – staff at banks and building societies are being encouraged to call the police if they have concerns, with Hertfordshire Police committing to give these calls a ‘blue light’ status.

In addition, says the report, trading standards officers immediately respond to reports of a rogue trader incident in progress.

And they give talks to community groups and other organsations that support elderly or vulnerable residents.

They also support the ‘Which? Trusted Traders’ approved traders scheme to provide a legitimate alternative to rogue traders.