The star of Charlie's Angels: Full Throttle said she heard the news of her supposed nuptials on the radio.
A Los Angeles radio station claimed Demi and Ashton were getting hitched in Las Vegas on Valentine's Day.
A shocked Moore called DJ Rick Dees straightaway to tell him the story had been completely made up.
A source told the Teen Hollywood website: 'It's something that started in the tabloids. It just kept getting repeated until it was being reported as true.'
Kutcher, 25, was said to have proposed to 40-year-old Moore after getting his mother's approval.
Several US media reports said Vegas had been chosen because that was where Moore married ex-husband Bruce Willis.
The Hart's War star had been tipped to be the one to give his former wife away.
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