An underworld trade exists between criminals who prey on vulnerable elderly people in distraction burglaries, police have revealed.

The addresses of elderly residents known to hold large amounts of cash in their homes are sold between thieves.

Officers involved in an operation to combat burglaries across the West country said there was evidence of a "shopping list" of lucrative addresses, which is sold amongst criminals.

Part of Operation Litotes, run by detectives from Devon and Cornwall, Dorset, Wiltshire and Gloucestershire involves getting people to protect themselves against bogus callers.

There have been cases of people travelling 400 miles to commit a distraction burglary at a specific address

Detective Sergeant Paul Bean

Detective Sergeant Paul Bean, second in command of the operation, told BBC News Online that elderly people were often "softened-up" by workers who carry out odd-jobs at their homes.

"A vulnerable elderly person usually pays over the odds for getting the trees cut or tarmacing the drive.

"If they pay in cash, that address becomes known as the home of a vulnerable person who has cash in their house.

"Knowledge of those addresses are passed on to distraction burglars," he said.

Police intelligence has shown that particular addresses are targeted by travelling gangs.

"There have been cases of people travelling 400 miles to commit a distraction burglary at a specific address.

Con men

"They have got to have a shopping list of addresses to travel that distance," he said.

Distraction burglaries are often repeated after information about prime addresses are sold between criminals, he said.

Nearly a quarter of homes which are burgled by bogus callers are visited again by con men within 18 months.

About 1,000 distraction burglaries are reported each year across the six counties involved in the operation.

Improve security

Det Sgt Bean said the money paid for the information depends on the amount of cash thought to be held in the house.

"If someone does a burglary at a house and gets a couple of hundred pounds, how much are you going to pay for that?" he said.

"If they get a couple of thousand pounds they are going to pay a lot more for that information."

Operation Litotes involves identifying elderly people who are vulnerable to bogus callers and encouraging them to improve the security of their homes, he added.