ELDERLY and vulnerable neighbours are being urged to be vigilant following a spate of rogue door knockers selling counterfeit products in Sunningdale. 

A warning issued on the parish council's website, advises residents to be wary of tricksters who have been operating in the area who pretend to be reformed ex-convicts attempting to mend their ways to scout out houses to burgle.

The fraudsters - known colloquially as 'Nottingham Knockers' as the scam is believed to have originated in the city - offer bags of dusters, cleaning goods and other cheap items for £5, £10 or £20 notes.

They are known to sniff the banknotes and if the money smells 'new' and looks crisp and flat as though it has come from a wad of cash, they believe the homeowner must have a stash of notes within the house. 

A notice on the council's website offers the following advice to residents if they receive an unwanted knock on their door.

It reads: "Look out through a window. If you see they have a large bag over their shoulder, you wave them away. You then phone vulnerable neighbours, to let them know and tell them, not to answer the door either. 

"If you answer the door, you only use these words, 'I am sorry, I do not buy goods and services at the door. Then firmly, but politely close the door and phone the police on 101.

"Everyone across the Thames Valley, uses these same words. When they hear them, they will know, not to bother with your road, as everyone is likely to be aware.

"You do not enter into any further conversation. They have had some minor training – their practised spiel in how to get a response from you – a sob story for example – trying to pay back to society, make their way or make an honest living. They have been known to show a card, saying they are deaf, dumb etc. Most are not true. It is to gain your sympathy – to establish how gullible you are!"

It also warns people to not inform the scammers that neighbours may be abroad or when they are out of the house. 

Residents are told to ensure that any tradesman carries the legal 'pedlars certificate' which entitles them to sell door to door.

A spokeswoman for Thames Valley Police said: "We have had several reports of this (crime) in the Windsor and Maidenhead area over the last few weeks and we advise people to ask for ID for anyone who calls at their home purporting to be selling."

However she confirmed that no burglaries as a result have been recorded.