Essex Police revealed information into the 'Nottingham knockers' who have been targeting households across parts of Essex.

The Nottingham knockers are doorstep callers who will offer a selection of household products for sale.

It's believed the scam originated in Nottingham which led to its name.

The people knocking on doors are often ex-convicts who claim they are part of a rehabilitation scheme supposedly the Government backed Community Payback scheme.

In fact, the Nottingham Knockers are likely to not be a part of any recognised rehabilitation scheme.

How do they scam people?

Through the scheme callers are given a bag of household products by someone who employs them. The bag contains a large number of items including tea-towels and they are charged a minimal sum for these items.

It used to be around £35 to £50 and they are allowed to keep whatever they make above this amount.

They are dropped off in an area by a transit van and are given a list of streets to work. After an hour or so, they are then picked up and dropped off in another location. They usually work from 9am to 9pm.

According to reports they knock on doors, offering cleaning items which they know are cheap and of very poor quality.

The scammers will note your address based on a number of factors

The homeowner will know that they are cheap - but this is a part of the scam.

Many people will pay for an item just to get rid of the knockers. There have been cases of elderly residents handing over large sums of money as these people can be very persistent and confrontational.

People will pay them in the form of a note and when the householder disappears to get this, this is when the scam begins.

When the note is handed over, the knocker will examine its condition and how long the person took to get it.

If it's crumpled, they accept it and move on. If its crisp, flat, new and likely to have come from a pile of new notes, they are much more interested and may engage the person in more conversation to get details about them.

Once they have left, they will smell the note. If it is slightly musty like it has been stored in a cupboard or under a mattress this is an indication that there is more in the property.

Those addresses are then noted. All addresses of elderly, vulnerable and gullible people are all noted.

Sometimes, the noted addresses are sold in prisons or pubs and revisited later and the occupiers then found themselves the victims of burglaries.

Essex Police have simply told people what to do in these situations: "Best practice, don't open the door."