A phone scam is conning innocent people out of hundreds of pounds – and you would not even know until your bill came in.

Unsuspecting victims have been hit with charges of more than £300 for calls lasting up to 12 hours, after receiving calls from an 08 number.

Having forgotten about the call, the mobile provider then sends users a message saying that they had been using a lot of minutes, according to reports in the Daily Mail.

Then, when a monthly bill is sent to the customer, it appears to be hundreds of pounds more expensive than the usual cost.

As victims call up to complain to customer services, they are told that records appear to show them calling the number and staying on the line for more than 12 hours.

Ofcom is currently investigating.

Has this happened to you? Get in touch by emailing andrew.colley@london.newsquest.co.uk