Elderly homeowners are being warned not to get sucked in by a firm of 'cowboy' damp proofers currently targeting Lancashire.

County trading standards officers believe that contact lists of potential victims are being used to telephone local people with a 'free damp check' offer.

Once contact is made a representative visits to carry out the check with a damp meter - but it is the vulnerability of the customer, rather than the presence of any damp, that triggers the hard sell.

The rogue traders use a number of tricks, including bogus cut price offers with costs ranging from hundreds to thousands of pounds being quoted, say county officials.

One 86-year-old complained about work being conducted on her property. Trading standards fficers arranged for a building surveyor to examine the house and it was established that the work did not need doing.

County Council deputy leader Cllr Doreen Pollitt says: "Our main concern is for people who do not have someone to turn to for advice.

" The work may be unnecessary and of little benefit to protecting the property. The elderly are particularly vulnerable and need help and support to protect them from unfair practice."

Anyone who receives a cold call or knows of someone who has been targeted is asked to call trading standards on 0845-600-1352.