Most people have a friend called Sarah, which is why people need to be particularly alert to this latest scam.

Fraudsters are texting people a message, which generally reads something along the lines of: "Hi its Sarah. I need you to do me a favour if possible. I had a small accident and broke my fibula and left elbow. Can you text me back once get this message x"

The message may seem plausible, but replying could see concerned friends being asked for £20 by the scammers.

Brentwood Live:

How the conversation progresses with the scammer

The texts are a variation of a scam which did the rounds last year, in which victims initially receive a text message from a loved-one which says they are in hospital and that the only way that they can make contact is via text message.

The text usually reads: “Mum i did try and phone from some else phone signal is really bad, there has been a terrible car accident. I’m in the ICU ward in hospital my phone ain’t switching on and needs charging. I’m on this mobile number please make sure you reply to this number, my friend didn’t make it he died before we got to hospital and his sister’s fighting for her life. Mum i had my seatbelt on, i’ve got a head injury but i’m ok. Going into Xray to be seen, please make sure you message me back and don’t phone cause mobile phones aren’t allowed here so please text in case I’m in there. I will go outside and phone you mum its really bad i need you to do me favour before it’s too late, as soon as you get my text please reply by text i need you to do me a favour mum, time is running out and i need you to do something mum”.

A spokesman from Action Fraud, which is warning about the scam, said: "These messages can quite easily evolve into more elaborate scenarios and are designed to play on your emotions and get you to react quickly without thinking.

"If you receive one of these text messages, don't send any codes or money, delete it and report it to us.

"If a family member was hospitalised, they would never be forced to use a mobile phone that required credit to activate it.

"To report a fraud and receive a police crime reference number, call Action Fraud on 0300 123 2040 or use our online fraud reporting tool."