Ananova:

Britons are being flooded with scam emails promising tax rebates ahead of this month's deadline for self-assessment forms to be sent in.

HM Revenue and Customs has issued the warning after a Sky News Online reported on a sophisticated new scam originating from Denmark.

The email tells the recipient they are due a tax refund and asks them for bank or credit card details so the fictitious sum can be paid out.

It uses the same stylesheet and graphics as HMRC, making it look genuine.

Lesley Strathie, HMRC chief executive, said: "This is the most sophisticated and prolific phishing scam that we have encountered.

"We only ever contact customers who are due a refund in writing by post. We never use emails, telephone calls or external companies."

An HMRC spokesman said it has been receving about 500 complaints a day about phishing scams.

It believes this is about 10% of the total number of fake emails sent - an estimated 50,000.

Anyone who provides their details to the fraudsters risks their accounts being emptied and credit cards used to their limit.

The victim could also find their personal details have been sold on to other organised criminal gangs.

HMRC has warned of more attempts to obtain personal information after the 31 January self-assessment deadline has passed.

That is when a large number of people will be waiting to hear about genuine tax refunds.

Anyone receiving an email appearing to originate from HMRC is asked to forward it unopened to phishing@hmrc.gsi.gov.uk