The police have warned householders to be on their guard after two men tricked the woman, in her 80s, into giving them money on Tuesday (3).
They subsequently took the cash and left without taking away the rubbish, a police spokesman explained.
DS John Walton, who is investigating the incident, said: "We believe these conmen are travelling across to the Isle of Wight and targeting elderly and vulnerable people.
"They are offering to buy items, which end up being stolen, or services in exchange for what is often a disproportionate amount of money.
"I would advise home owners to always check the credentials of unknown callers and contact the police immediately if they receive a suspicious caller or see any suspicious vehicles in their area.
"We understand that sometimes people feel embarrassed to get in touch with the police after being tricked or duped, but we would urge anyone who has been a victim of a distraction scam to get in touch with us by phoning 101.
"Remember — lock, stop, chain and check. If you are unsure about a caller, do not open the door."
The police have offered the following crime prevention advice against such callers:
Always use the door chain when answering the door. If you are not sure of the caller, do not open the door.
• Always check the credentials of unknown callers. Do not phone the number on the ID card, use a phone book or a bill.
• Never employ cold-calling doorstep traders or engage with cold callers on the phone.
• Do not keep substantial sums of money in the home.
• Always keep front and back doors locked.
• Consider joining or setting up a 'No Cold Calling Zone' or Neighbourhood Watch scheme.
• Report any suspicious callers or activity to the police immediately.
• Keep an eye on elderly or vulnerable neighbours, friends and family.
Anyone with information can contact DS Walton, of Newport CID by phoning 101. Information can be given anonymously by phoning Crimestoppers on 0800 555 111.