GANGS of criminals who pose as workmen to prey on the old and vulnerable will be targeted by an elite police squad after a three-month pilot scheme proved successful.

The new team, based at Durham, will be given an 18-month remit after Operation Bombay this summer resulted in a dozen arrests of prolific criminals from around the UK.

One of those caught was later arrested and questioned in connection to a murder which took place during a bogus official incident.

The operation, which included officers seconded from Durham, Northumbria and Cleveland forces, has proved to be such a success other forces are now keen to learn from it.

Police said traditionally investigating bogus caller crimes had always been difficult because the offenders often had transient lifestyles and the crimes often crossed borders.

Detective Chief Inspector Ken Donnelly said: "The people who deliberately target pensioners in their 70s, 80s and 90s, trick their way inside and steal, are highly organised.

"They use high-powered stolen motor vehicles with false plates. They are persuasive, ruthless, daring - and at times violent. In fact, there have been a number of offences in our region where violence has been used."

He said the police also thought from the work done that information is passed between criminal gangs to enable them to find easy targets, with the same information distributed to rogue traders with high-pressure sales teams.

Det Ch Insp Donnelly said: "These thieves will pocket anything from a few pounds upwards. One individual from our region had £25,000 stolen in one go.

"But it is not just the loss of hardearned savings. The victims are left traumatised by what has happened and very insecure.

"Sadly, this is a crime which is massively unreported for many reasons.

The elderly victims are embarrassed; they are concerned they will be inviting unwanted attention to themselves; they fear they won't be allowed to continue living independently, but they are also frightened of the court process.

"The work of our regional team has shown that these gangs, the majority of whom are in their late teens to mid- 20s and, in a national sense are prolific offenders, can be effectively targeted."