Thieves who steal from vulnerable old people by conning their way into their homes could be much more active than previously thought.

A new survey suggests "bogus caller crime" is 16 times more prevalent than official Home Office figures show.

The research commissioned by the British Gas Help the Aged Partnership estimates that about 300,000 elderly people were targeted by bogus callers last year.

Half of the victims did not report the incident to the police.

Singled-out

Bogus callers pose as utility workers, trades people and even police officers to gain entry into older people's homes.

Bogus Caller Survey facts

51% of older people fail to report bogus caller incidents to police 25% of older people open the door without employing any precautions 23% of women aged over 60 worry every time they answer the door to unknown callers. Fact here Source: British Gas Help the Aged Partnership

They often work as part of a highly organised criminal group.

The survey revealed that a quarter of those over 60 open their front door without taking any precautions and four in 10 are unaware of public campaigns to raise vigilance on the doorstep.

Their mainly female victims have an average age of 78, and are targeted because they keep cash and valuables in the home, are more trusting, have regular routines and are least likely to be able to defend themselves.

The effect of such crimes can be devastating, with victims suffering heart attacks, strokes and worsening mental health.

Improving front door security

Different police forces record this type of burglary in different ways so this is the first time that the real extent of the crime has emerged.

The Home Office is considering a call by Help the Aged to make bogus caller theft a separate recorded offence and devote more resources to tackling it.

The organisation's partnership with British Gas has already made a raft of new services available to older people.

These include a Handy Van service, which is a fleet of 36 vans that travel around Britain to help install security devices such as spy holes and mortice locks for pensioners free of charge.

Spokesman for the British Gas Help the Aged Partnership, Adam Blight said: "The service tries to be as reactive as possible and we often liaise with police forces to go to areas experiencing a particular problem with bogus callers."

A second initiative is the Seniorlink, a device which can be installed in a pensioner's home to provide direct access to a call centre which can immediately verify the identity of the caller.