SYDNEY — Sweden's Therese Alshammar broke her own 50-meter butterfly world record at the Australian swimming titles Tuesday but was later disqualified by Swimming Australia for wearing two swimsuits.

World champion Alshammar set a time of 25.44 seconds in the morning qualifying heats to take 0.02 of a second off the record 25.46 she set at Barcelona, Spain on June 13, 2007.

But officials later discovered that Alshammar was wearing two suits in the race and ruled that the time would not stand. Swimming Australia said that under swimming governing body FINA's new rules that were ratified last weekend, and Swimming Australia's rules instituted last year, Alshammar would be disqualified because it states that swimmers may only wear one suit.

Alshammar had initially planned to appeal the decision, which came after a five-hour meeting. But later Tuesday, Swimming Australia spokesman Ian Hanson said Alshammar had withdrawn her appeal.

Alshammar told Swedish national broadcaster SVT that she wore two swimsuits because it makes her feel more comfortable.

"In case your swim suit bursts, it's nice to have a double," she said. "I have a regular swim suit under my performance suit because it makes me feel more secure and it covers more of my chest."

Alshammar said the extra swimsuit didn't help her performance. The main reason the limit was introduced was because of concerns that new technology was increasing buoyancy for some swimmers.

"It's not something that makes you swim faster. If anything it makes you slower to have such a swimsuit underneath," she said.

She said she knew about the new FINA rules but wasn't sure whether they had already come into effect.

Australia head coach Alan Thompson was blunt when asked if he felt Alshammar was cheating.

"Well obviously, I guess in general terms any breach of the rules is cheating," he said. "The main point to be made is that she wore two swimsuits and it was quite clear on the video and it was noticed by quite a large number of people around the pool this morning."

Triple Olympic gold medalist Stephanie Rice said she was surprised that a swimmer would make such a mistake, given the attention the FINA rules had been given.

"It is a bit surprising that people are still wearing two suits after they (FINA) made the rules," Rice said.

Last Saturday in Dubai, United Arab Emirates, FINA adopted new rules for the high-tech suits that helped produce more than 100 world records in just over a year.

The guidelines "revise the requirements for swimsuit approval" and it was said they would be in place for the world championships in Rome starting July 17. Among other amendments, FINA stipulated that swimsuits should not cover the neck and will not extend past the shoulders and ankles.

The 31-year-old Alshammar would not have had another chance to break her mark at the Australian championships. As a foreigner, she is not allowed to compete in semifinals or finals and there is no B final for the race.

Alshammar, the reigning world champion in the non-Olympic event, has been training with Australian swimmers in Sydney for the past two months.

Alshammar had a disappointing Beijing Olympics, heading to last year's Games as a strong medal prospect in the 50 freestyle. But she missed the final at the Water Cube after she discovered a tear in her swimsuit just before the start of her semifinal, and failed to qualify for the last eight.