Simon Cowell apparently upset fellow Britain's Got Talent judge Amanda Holden by making a rude remark about her ex-husband Les Dennis.
At the latest auditions at the London Palladium, actress Amanda made a comment that she "went from rags to riches", Metro reports.
Simon is said to have sniped: "You went from Les Dennis", referring to her eight-year marriage to the comedian.
Amanda hit back: "That's a bit close to the bone, Simon."
The jibe reportedly caused a frosty atmosphere at the London auditions for the ITV1 show and the 53-year-old media mogul was forced to apologise to Amanda, telling her: "I'm sorry, I didn't mean it."
Meanwhile, Amanda revealed she doesn't plan to reveal anything nasty about Simon in her autobiography, due out in the autumn.
She said: "I'll have to wait until he's dead to come out with the truth. It's an honest book but no one needs to be worried. It's a book I want my daughter to be proud of."