Fraudsters posing as police and bank staff are targeting elderly and vulnerable people.
Police are warning residents about a telephone scam in which the caller claims to be a police officer, saying he has someone in custody who has been caught using a copy of the victim’s bank card.
The fraudster then asks the victim to take their card to a police station, asking for the card’s PIN as well.
Victims who are targeted will usually not be able to physically take their card to a police station so the swindler will suggest a courier to pick it up.
When the card has been collected, the victim's bank account is emptied.
The con-artists will ask the victim to call their bank immediately to cancel their card. But the suspect does not hang up, so the victim thinks they are talking to the bank when they are still speaking to the criminals.
This is then followed by the criminals using unsuspecting cab companies to make collections, as well as someone claiming to be a motorcycle courier.
Detective Constable Emily Bugg of Enfield CID says there have been five incidents since January 16.
She said: "This means that there are five members of our community who have been preyed upon by criminals and who now face the unenviable task of dealing with the lasting effects of becoming a victim of crime.
"If you are related to, or care for someone who may be vulnerable to this crime please make sure that they are aware of these fraudsters and if they are in any doubt that a caller is genuine please tell them to hang up and call Police on 101 or contact their Safer Neighbourhoods Team, making sure they use another line or check for a dial tone before ringing."