Scammers have been extorting money from pensioners by telling therm they are being fined over disposal of waste following building work.
Police are warning elderly and vulnerable people who have had work done on their houses not to be taken in by con-artists who have been going around telling people they are from Trading Standards or the Office of Fair Trading and they are being fined for inappropriate dumping of contaminated waste.
One woman in her mid-80s paid £12,500 to tricksters in a number of bank transfers after she was told she had to pay several fines. A man, also in his 80s and from Wallington, almost fell victim to the scam but decided against handing over any cash. Both incidents happened in December.
Detective Constable Natalie Laing of Sutton CID said people should not make payments or reveal their bank details to anyone who calls at their door without prior appointment. She added: "Please tell a trusted family member or friend what has happened and report such incidents to police on 101."
An investigation into the incidents led to four men, one aged 18, the others all in their 20s, being arrested at addresses outside Sutton on suspicion of money laundering. All four have been bailed pending further enquiries.
If you have any information or think you have been approached by the scammers, you can call police on 101 or the charity Crimestoppers on 0800 555 111.