A conman pensioner cheated an 83-year-old homeowner out of £250 by claiming to have repaired his leaky guttering.
The elderly trickster, who said he was 74, told the victim he had seen water trickling from his house in Thornton Heath and offered to fix it.
He claimed to have stopped the leak an hour later and asked for £250 from the homeowner, who assumed his cataracts had prevented him from spotting the problem himself.
But when the victim's wife returned home she could see no evidence of any work being done and reported the incident to the Citizens Advice Consumer Service.
Croydon Council's trading standards team are now investigating the scam, which took place in November.
Councillor Simon Hoar, cabinet member for community safety, said: "This case is worrying because the conman obviously played upon the fact that one elderly person wouldn’t suspect another of the same age group conning them.
"Sadly, elderly residents should treat with caution any stranger who comes to their door. They should not let them inside until they’ve seen and verified some form of identification.
"The matter is being investigated by our trading standards officers, who, once again are urging residents to never agree to allow cold callers either into, or to undertake any work on, their home."
The conman was white, of medium build and about five feet nine inches tall.
Anybody who may have been approached by this man, or somebody similar, is asked to report it to Citizens Advice Consumer Service on 0845 404 0506.