Money and finance expert Martin Lewis has issued an urgent warning for all those who use social media apps Facebook and WhatsApp.

We've put together everything you need to know.

What has Martin warned WhatsApp and Facebook users about?

Martin has warned of fake posts going round on other social media platforms about an 'extremely sophisticated' scam involving banks.

What does the scam say?

The posts, which have been circulated on Facebook and WhatsApp, mentioned that recipients get a message saying payment hasn't been taken from O2, Vodafone, Three, GiffGaff or EE and they should click on a link.

"As soon as you touch it you money is gone," the viral warning adds.

It then went on to say that banks have been inundated with calls, and that Martin Lewis confirmed it this morning.

What was Martin's response?

Taking to Twitter to share his response, Martin said: "This viral scam alert's nowt to do with me..

"I've NOT talked about it. Always be scamaware, but this sounds nonsense."

However, Martin added that it's not an excuse to relax about scams.

He continued: "If you do get scam texts/emails it describes, it's likely phishing for data, so delete.

"Yet the scam alert's no better and ain't from City of London Police as far as I know."

What have Action Fraud said?

Action Fraud - who are part of the City of London Police - said back in March that an incredibly similar message was nothing to do with them.

In a statement, they said: "We are aware of a rumour currently circulating via WhatsApp, SMS and social media which references the City of London Police Fraud Team and claims that Danske Bank customers are being targeted by a particular text message (smishing) scam. The content of this message is false.

"However, smishing scams are common. Don’t click on the links or attachments in any suspicious emails or texts, and never respond to messages that ask for your personal or financial details.

"It’s important to remember that your bank would never ask you to move money out of your account, or contact you out of the blue and ask for details such as your full banking password or PIN.

"Anyone who has divulged information after receiving this type of message should contact their Bank immediately."

What advice should people follow if they have been a target of fraud?

Action Fraud have shared the following advice for those who think they may have been a target of fraud.

  • Be wary of clicking on unsolicited messages on social media, email, texts or WhatsApp - even if they appear to come from a trusted contact.
  • Do some online research first - check the official website to see if there is any information available.
  • Ensure that you have anti-virus software on your computer.
  • Never give out personal or financial data including usernames, passwords, PINs, ID numbers or memorable phrases.