Hamburg - Just as in Athens four years ago, Australia and the Michael Phelps-led United States will once again battle it out for supremacy in the pool when the two countries' swimming teams meet at the Olympic Games in Beijing.

While the US has traditionally dominated the sport, the rivalry with Australia has grown significantly over recent Games, with the contests in the Water Cube likely to be no different.

The US has won a total of 458 medals in swimming, including 202 gold, while Australia lies a distant second with 157.

Four years ago the US once again topped the list with 28 medals, including 12 gold, followed by Australia with 15, of which seven were gold.

Michael Phelps won six of America's gold medals and the 23-year- old will be hoping to exceed that remarkable figure this time around and eclipse Mark Spitz's record of seven golds at a single Games, achieved in 1972 in Munich.

Phelps won five titles at the US trials in July and will compete in the 100-metre and 200m butterfly, the 200m and 400m individual medleys, the 200m freestyle and is set for three relay appearances as well in a total of eight starts.

Australian Andrew Lauterstein could challenge Phelps in the 100m butterfly but it is hard to see where else the American will slip up in his historic quest.

Another man heading into Beijing on top form is distance swimmer Grant Hackett, winner of five Olympic medals and defending 1500m champion. The 28-year-old Australian set a new world shortcourse record in the 800m freestyle in the run-up to the Games and competes in the 200m free, 400m free and 1500m free.

In the men's 50m freestyle, compatriot and world record holder Eamon Sullivan will start as favourite ahead of Garrett Weber-Gale, winner of the 50m and 100m freestyle at the US trials.

On the women's side, the 41-year-old Dara Torres becomes the first American swimmer to compete at five Olympic Games, having already won nine medals, the first a relay gold coming in 1984.

Katie Hoff has qualified for six events and could break the record for most medals won by a US woman swimmer at a single Olympics, which currently stands at five and is jointly held by Shirley Babashoff, Torres and Natalie Coughlin.

Coughlin won two gold at Athens in 2004 and will be competing in the 100m backstroke, 200m individual medley, 100m freestyle and 400m relay this time around.

Australian Libby Trickett (formerly Lenton), holder of five world records and four World Championship golds, will be hoping to increase her Athens haul of one 4x100m freestyle relay gold and a 50m freestyle bronze.

The 23-year-old is entered in five events, including the 100m and 200m freestyle, as well as the 100m butterfly.

Other swimmers to watch are Leisel Jones in the breaststroke and Jessicah Schipper in the butterfly.

Apart from the Americans and Australians, Japan's Kosuke Kitajima will be confident of defending his 100m and 200m breaststroke titles while China's Wu Peng will look to give the home crowd something to cheer for when he goes up against the mighty Phelps in the 100m and 200m butterfly. (dpa)