Officials at a downtown Las Vegas casino say about 550 singles took part in an attempt Friday night to hold the world's largest speed-dating event.

While that's more than the 484-person record listed by Guinness World Records, organizers said they are still uncertain whether enough singles stayed for the entire "D Date-a-Thon" Valentine's Day event to qualify it for the record books.

Singles talked with 24 potential mates for three minutes each in hopes of finding a match. Monitors were on hand to ensure singles actively participated in the dates, or they could be disqualified from the final tally for record-setting purposes.

An outside auditing firm that oversaw the event for The D Las Vegas casino and other sponsors is trying to verify how many of the 550 registered participants stayed within a fenced-in area for all 24 dates, spokeswoman Maddie Meister said.

"If each person is deemed eligible, we broke the record," she told The Associated Press on Saturday. "There were some people who left to go to the restroom, and they could be disqualified. They're calculating how many people exited and how many can be considered legitimate participants."

Paperwork will be submitted to Guinness World Records if the auditing firm determines the record was broken, Meister added.

The current record was set in Ho Chi Minh City, Vietnam, on Nov. 30, and the event was organized by a Singaporean company, according to Guinness World Records.

The Las Vegas event generated a registration line of about 1,000 singles at one point, Meister said, but many left because of the long wait. It was held at the site of the popular Fremont Street Experience.

Some singles continued dates with matches at nearby bars afterward.

Participants were plied with $1 drinks, music and prizes, including hotel stays and helicopter rides.