MANCHESTER, - Australia's recent record-breaking performances will count for nothing if their swimmers cannot reproduce that form at the Beijing Olympics, according to triple gold medallist Grant Hackett.

Grant Hackett [Agencies]

Hackett, who is aiming to become the first male swimmer to win gold in the same event at three successive Olympics, said eight world records at Australia's Olympic trials last month had given the team a major boost, but the United States would still be the favourites in Beijing.

"We feel confident but we feel that's only the start of what needs to be done," he told a news conference at the world short-course championships in Manchester on Saturday.

"Those trials surprised a lot of people in Australia. We didn't expect to break eight world records and have so much depth in many races.

"The team is confident but we're not getting ahead of ourselves," added the 27-year-old, who will be aiming for a third straight 1,500m title in China.

"The Olympic Games is where the real results will be posted and remembered.

"No one remembers the Olympic trials. We're confident, proud of the way we performed, but the job's not done yet."

Australia's best result at an Olympics was as hosts at the 2000 Games, when they took 18 medals in the pool. However, Australian swimming chiefs expect their team of 22 women and 20 men to better that mark in Beijing.

Unlike most of the world's top swimming nations, who hold trials earlier in the year, the U.S. will have their qualifying event just five weeks out from the Aug 8-24 Games.

Hackett predicted U.S. swimmers will raise the bar at their trials by adding to the rising tally of world records set so far this year.

"They're going to have an unbelievable performance," he said. "They'll be the number one team going into the Olympics, no doubt about that.

"Their performances lately have been great and their swimmers have not even been rested."

Hackett will enter unknown territory in Beijing when he competes in the 10-kilometre open water event, which he said would be the "ultimate test" after a career spent only in the calmer waters of swimming pools.

"I'm not experienced in this field. The best thing is the element of surprise," he said. "People don't know what I'm capable of. I've worked on my preparation, I'm as fit as I've ever been."