Britons are being warned of a surge in fake Health Lottery letters in circulation, claiming households have won hundreds of thousands of pounds.

Consumer champion Which? reported that Google searches about the letters have spiked in recent weeks, and the Health Lottery has said they have the potential to be “extremely harmful”.

According to Which? the new scam letters, addressed to people by name, claim they’ve won staggering figures - some up to £750,000. It also includes bogus winning numbers, as well as a ticket number.

The letter also falsely claims to be sent from an address in Aberdeen, which is not affiliated with the Health Lottery.

People are told they have been “randomly selected by Computer Ballot System” from a “database of the National Health Service and Residents in the United Kingdom.”

They are then given two phone numbers to call to claim their winnings. However, calling these numbers will lead to a phone scam where the fraudster will attempt to gather personal and financial information.

A spokesperson for the Health Lottery told Manchester Evening News that it was "incredibly frustrating" to see the fraudulent letter circulating again.

They said: "This potentially extremely harmful scam rears its head from time to time and spreads confusion and distrust in our much-loved brand.”

They added: “The letter itself is complete nonsense, describing huge jackpots which are not even legal under the terms of The Gambling Act.”

The Health Lottery was launched in 2011 to raise money for health-related causes across the country. Participants enter by selecting five numbers and prize draws take place five days a week. The top cash prize is £100,000.

How to spot a fake Health Lottery letter

The Health Lottery “never” sends letters to people who win. If someone receives one of these letters, they’re advised to report it and then bin it.

Warwickshire County Council’s Trading Standards Service alerted residents about the scam circulating locally in December.

According to Which?, Warwickshire residents received letters claiming they'd won as much as £420,000 in the Health Lottery.

People can report fraudulent post through the Royal Mail’s scam letters service form, which can be found here.

People can also report any scams to Action Fraud on 0300 123 2040. More independent advice and support can be found via Citizens Advice’s consumer helpline on 0808 223 1122.