Victims of an HM Revenue & Customs (HMRC) scam in Watford and surrounding areas have lost thousands of pounds.

Hertfordshire Constabulary says 17 elderly and vulnerable victims were contacted by fraudsters claiming to be the HMRC over the last few weeks - and were told they had outstanding debts or unpaid taxes in their names.

The fraudsters then asked the victims to make bank transfers as payment, police said.

Police said the victims, who were targeted in Cheshunt, Hatfield, Hemel Hempstead, Stevenage and Watford, have lost a total of £10,855 so far.

The fraudsters cold call victims using a spoofed number, sometimes leaving voicemail messages claiming that they owe unpaid tax to HMRC.

The victims are asked to call back on the number provided, through which they are told that there is a warrant out in their name and if they do not pay, the police will arrest them.

Victims are also sometimes contacted through text messages asking them to urgently call the number provided.

Now, police are urging residents to stay vigilant.

Detective Inspector Rob Burns, from Hertfordshire Constabulary’s Serious Fraud and Cyber Unit, said: “These fraudsters tend to target elderly and vulnerable people and use the threat of arrest to frighten them into making bank transfers or buying the gift cards.

“It’s important to remember that government official and police officers will NEVER contact you in these ways or ask you to buy gift cards, vouchers withdraw money, purchase goods or hand over private banking details.

“Please help us to raise awareness by talking about this with your friends and family, especially if they are vulnerable or elderly.”

Police have issued the following advice following the scams:

• HMRC will never use texts to tell you about a tax rebate or penalty or ever ask for payment in this way.

• Telephone numbers and text messages can easily be spoofed. You should never trust the number you see on your telephone display.

• If you receive a suspicious cold call, end it immediately.

Hertfordshire Constabulary offers the following advice on recognising fraud:

• Be sceptical of callers, even those who claim to be officials.

• Don’t be afraid to put the phone down with a brief ‘No, thank you’.

• NEVER give personal information, such as your date of birth or bank details, to unexpected callers.

• Remember that the police or your bank would NEVER unexpectedly call you and ask you to withdraw cash or move your money to another account, as a result of fraud or any other reason.

• If callers suggest you call your local police or bank to check who they are, use another phone or ensure the line has been fully disconnected by phoning a friend or relative first, or by waiting at least five minutes, otherwise you may think you’ve phoned a number, but you’re simply talking to the fraudsters again. This is a common fraudsters’ tactic.

• If a caller asks you to type your bank PIN number into your telephone handset - do not do this, as fraudsters can use technology to identify the numbers.

• You can opt out of many cold calls by registering for free with the Telephone Preference Service on 0845 070 0707.