TAMPA, Florida (AP) - The idea behind the Tampa Women's Club charity event was simple. For US$20 (S$25), you could buy a flute of champagne and a chance to win a one-carat, US$5,000 diamond.

Organizers of the Saturday event placed US$10 cubic zirconia stones in the bottom of 399 of the 400 champagne glasses. The prized diamond, donated by Continental Wholesale Diamonds, was placed in the last.

The problem? Eighty-year-old Miriam Tucker accidentally swallowed it.

Ms Tucker told local news media that she didn't want to put her finger in the champagne, so she drank a bit. While laughing with women at the table, she realised that she swallowed it.

Embarrassed, she had to tell jewelers who were frantically searching for the winner.

Already scheduled for a colonoscopy on Monday, she had a doctor recover the jewel.