Bogus builders tricked an 80-year-old woman out of almost £200 and even drove her to the bank to collect the cash.
The fraudsters called at the woman's home in Elgin Road, Sutton, and said her chimney needed repairing at around 11.30am on Tuesday.
One of the men climbed on the roof and the woman was told they would repair her chimney there and then if she could pay them £180.
The other man drove her to the bank and asked her to withdraw £180. Police were notified of the transaction by the bank but only after the customer had left.
When police arrived at the woman's house the workers had left. Further investigations revealed no repairs had been made to the chimney.
The victim of the scam is upset and annoyed with herself for falling for the scam.
Sergeant Kathy Morteo wants people to let police know if they have had anyone making unsolicited calls to their house from builders offering to carry out work.
She said: "It is quite likely that they may have called on other residents nearby. If they did so, please let us know."
Anyone who has any information can contact police on 020 8721 2494.
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