Therese Alshammar of Sweden set a world record in the 50-metre butterfly on Tuesday. (Jessica Gow/Associated Press)

Therese Alshammar of Sweden lowered her own world record in the 50-metre butterfly at the Australian titles and world championship trials on Tuesday morning, but the new mark was removed because of recent revisions to the rule governing swim suits.

Alshammar, 31, clocked 25.44 seconds in her qualifying heat at the Sydney Olympic Park Aquatic Centre, shaving 0.02 seconds off the world record she set at a meet in Barcelona, Spain, on June 13, 2007.

But Swimming Australia officials later discovered that she wore two suits during the race, which is no longer permissible under revised requirements ratified last Saturday by FINA, the governing body for swimming.

Swimming Australia spokesman Ian Hanson confirmed she will appeal the decision.

Alshammar, the reigning world champion in the non-Olympic event, has been training in Australia the past two months.

"I have had a great couple of months in Australia," she said. "It is the best place in the world for swimming."

Alshammar won silver medals in the 50 and 100 freestyle — losing both events to Dutch sensation Inge de Bruijn — and a bronze in the 4x100 freestyle relay in the same pool at the Sydney Olympics in 2000.

With files from the Associated Press