PEOPLE in Oxford have been warned to be on guard against 'Nottingham knockers'.

The Neighbourhood Watch alert was shared by Thames Valley Police yesterday.

It stated: "Some doorstep callers may offer poor quality goods at inflated prices and if a caller is not genuine, they may be gathering information for future crime."

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The alert went on to explain the sellers may say that they are on a 'rehabilitation course' arranged by the probation service but this is not true and they are often known criminals.

According to police, a bag of household products sold by the cold callers is supplied by someone who employs them, originally a man from Nottingham – hence the name, but now they are recruited from anywhere.

They are believed to make a note of vulnerable people to target in the future.