Sir Alan Sugar, a business magnate known for his remarks on the BBC TV series ‘The Apprentice’, has recently warned against bitcoin-related scams using his name, pretending he is endorsing an investment in the cryptocurrency with the organization.

The business magnate’s warning came through social media, where he claimed the scammers were “scum,” and asked his nearly 5.5 million followers to share the message, so no one would fall for their tricks.

Specifically, Sir Alan Sugar warned against Bitcointrader, an organization allegedly run by scammers who attempt to sell individuals cryptocurrencies, but merely take the money victims send over. When told to sue them, the business magnate revealed that his lawyers were “on the case trying to track them down and hand over to the police.”

In a follow-up tweet, he noted that a 74-year-old would-be investor fell for the scam, as it was using his image to imply endorsement. According to the tweet, the individual was tricked into registering on Bitcointrade through a misleading article, and then received a call from the scammers, who persuaded him to invest £250 ($337), while claiming they would call back.

Sugar advised the individual to call his credit card company to get the funds back, but the number of victims falling for similar scams is unknown. These reportedly mostly target old people, as these “think it is new way of making money and get sucked in because they show me [Sir Alan Sugar] and other people as endorsing it.”

According to the UK’s national fraud and cybercrime reporting center, Action Fraud, in March consumers were tricked into sending cryptocurrency scammers a total of £34,000 (about $45,800) in 21 separate cases.

Notably, various other celebrities have seen their images used to promote fraudulent cryptocurrencies and initial coin offerings (ICOs). Some of these celebrities include TV star Deborah Meaden, known for her role in the series Dragons’ Den, and Money Saving Expert founder Martin Lewis.

Lewis has in the past denounced these scams, and notably sued social media giant Facebook for failing to stop ads, which included get-rich-schemes, from using his face and name. At the time he said:

“Enough is enough. I’ve been fighting for over a year to stop Facebook letting scammers use my name and face to rip off vulnerable people – yet it continues. I feel sick each time I hear of another victim being conned because of trust they wrongly thought they were placing in me. One lady had over £100,000 taken from her.”

Martin Lewis

Notably, Facebook has decided to ban cryptocurrency and binary options-related ads earlier this year. The move saw Google, Twitter, and recently Microsoft’s search engine Bing follow its footsteps.