The All Rise singer – who is taking part in the new series of Channel 4's social media reality show The Circle – revealed he had £5k stolen from his account after replying to an email he believed to be from the government tax authorities.
James, 42, said: "There are lots of catfishes out there, you can never really trust anybody.
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"I've been stung before.
"I got an email from a fake HMRC telling me about a tax rebate that I had to give my details. I didn’t think and just handed it over. And then my accountant was like, 'HMRC will never ask for your account details. They have them. You don't need to do that.'
"And I was like, 'S***, what have I done?' and then I looked in my account and they had cleared me out. They took about five grand."
He added: "Thankfully, the bank knew. I had to send in the emails that I had, and I got my money back."
The former boyband singer is among the celebrity line-up for the latest series of The Circle – which sees contestants interact with each other online and therefore choose how much of their true selves they present to one another.
James said: "I want to go in with a bit of a blank canvas. I want people to think that potentially I might not be who I am because then I think you can play that to your advantage. But I also want to go and be me."
The bisexual singer – who has a 16-year-old daughter Tianie from a relationship with ex-girlfriend Claire Grainger – revealed he has spent lockdown living with his mum.
He said: "It's just nice to get out of the house and have a little bit of me time."
Other celebrities taking part in the new series in aid of Stand Up To Cancer include Loose Women's Kaye Adams and Nadia Sawalha, drag queen Baga Chips, Geordie Shore star Charlotte Crosby and EastEnders star Denise Van Outen.
The six-part celebrity series will air from Tuesday 9 March, 2021.
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