Scammers tricked an elderly woman out of more than £20,000 over the last six years after she replied to a single letter.

The vulnerable 76-year-old from Sutton has been plagued by six to 10 items of junk mail every day after first replying to a single fraudulent letter in 2006.

Since then the con-artists tricked her out of an average of £300 per month until Sutton Council's trading standards team stepped in.

Now, after the scam was uncovered by an intelligence-led operation, she has stopped replying to letters about bogus prize draws, fake clairvoyants, non-existent foreign lotteries and purveyors of so-called miracle cures.

Sutton Council's trading standards team has urged people to be vigilant against tricksters and not to answer unsolicited approaches, whether in the post, over the phone or in person.

Councillor Richard Clifton, the council's lead member for revenues and benefits, said: "This is a particularly callous crime.

"The conmen prey on vulnerable people who receive more and more bogus offers every day.

"I urge anyone who receives a letter from these people to bin it, if you get a call put down the phone and if they ring the bell firmly shut the door."

People are encouraged to ignore any offers which come out of the blue or ask for cash in advance.

If you suspect something is a scam you can call Action Fraud on 0300 123 2040, visit www.actionfraud.police.uk/contact-us or call The Citizens Advice Consumer Service on 08454 040506.