Doorstep callers selling household products – who claim to belong to a rehabilitation scheme – have been targeting areas of Ipswich, Kesgrave and Woodbridge.

Suffolk Trading Standards said it received reports of “Nottingham Knockers” operating in the county yesterday attempting to sell low-value household products, often of dubious quality, at hugely inflated prices.

These callers may claim to be ex-offenders attempting to mend their ways, but they are not part of any recognised rehabilitation scheme, according to authorities.

The term Nottingham Knockers arose as it is believed the scam first originated in the Midlands city.

Suffolk Trading Standards posted a warning on its Facebook page advising people never to buy anything from the cold callers and to report them on 03454 040506.

Suffolk police issued the following advice on how to deal with cold callers:

• Always ask for identification from any unexpected callers and do not let anyone in if you are not comfortable with who they are and verify their identity with the company they work for.

• Always use the chain and viewer on your door to see who is calling. Only open the door if you feel comfortable and always keep the chain on.

• Councils and utility companies will generally contact householders by telephone or letter if they plan to carry out repairs rather than make unsolicited calls.

• If you have a back gate ensure that it is locked with a padlock. A slide bolt is not sufficient on its own.

• Ensure that your doors are kept locked when you are in the house.

• If you need carers or family to have access then consider fitting a key safe on the outside wall near to the front door.

• If anyone calls claiming to be from the utility companies such as water, gas, electricity or the council, do not let them in unless they can quote to you on the doorstep your personal account number which is found on your bills. If you are at all suspicious then phone the police immediately.

Anything suspicious can be reported to police on 101.