Dragons' Den panellist Theo Paphitis told a Norwood audience how a contestant on the BBC show swindled him out of £80,000.
Credited with turning round failing chains including Ryman and La Senza, the Cyprus-born entrepreneur held court on a variety of business issues before a breakfast audience of 200 at a central London hotel.
Mr Paphitis - who has five children with his Jewish wife Debbie - was interviewed by Norwood trustee Neville Kahn.They discussed everything from why companies should encourage charity work and the prospects for small businesses to the battle for the post-Games use of the Olympic Stadium.
He also recalled how he and fellow Dragon Peter Jones had been "absolutely legged over" by one contestant.
They were enjoying a celebratory glass of champagne when they discovered that the man whose enterprise they were investing in had made off with the money.
"The reality in business and in Dragons' Den is you win some and you lose some," Mr Paphitis said. "The great ones make great business, but there are others where I have lost my shirt."
Set to launch lingerie chain Boux Avenue next month, he was enthusiastic about the venture, which will start with six stores. It would be selling "exceptional products", he claimed, which would please even fussy Jewish women.
The breakfast raised £90,000 for Norwood, which the speaker praised fulsomely. "It epitomises everything that charitable work should be for and does so with staggering efficiency and delivery."
Organiser Sara Parish said that "every pound raised will benefit the many thousands of people with learning disabilities, and children and families in need, who rely on our life-changing services each year".