Aussie Cate Campbell smashes 100m free world record

Australia's Cate Campbell smashed the long-standing women's 100m freestyle world record on Saturday at a meet in Brisbane, firing an ominous warning to her rivals ahead of the Rio Olympics.

"We present your new world record holder in the 100 free," tweeted the Australian Swim Team, confirming the 52.06 seconds swim which eclipsed German Britta Steffen's old mark of 52.07 set in Rome in 2009 during the high-tech supersuit era.

Campbell, 24, had "put the world on notice" at the Brisbane Grand Prix, it added, with Australian swim great Dawn Fraser poolside to witness the new record.

She had already notched an impressive win over her sister and main rival Bronte, the reigningworld 100m freestyle champion, in the 50m freestyle on Friday.

"I still can't believe it's happened," Campbell told reporters after her win.

"People have been asking me when I was going to break the world record for the last three years and honestly it wasn't really on my mind but every time I got in the pool, it was like will they stop asking me this question now. Now you will."

Australian media reported that Campbell was the nation's first individual world-record breaker since the drag-reducing, muscle-supporting polyurethane supersuit era.

The sport's governing body FINA outlawed the suits in 2010 following a storm of criticism afterworld records tumbled at the 2009 world championships.

Going into Saturday night's swim, Campbell said she had not been aiming to be the fastest woman to swim 100 metres in the world, but was trying to remain relaxed and focused.

She said of her world record swim: "It was a really controlled, smart swim, it was what I was working towards doing over the last year or so."

Campbell had shoulder surgery in late 2014 which left her not fully fit at last year's worldchampionships in Kazan, Russia when she claimed bronze behind sister Bronte.

But in April, Cate edged her sister to win an epic 100 metres freestyle final at the Australian Championships and Olympic trials in Adelaide.

The Campbell sisters headline a 34-strong Australian swim team heading to Rio, with several ranked world number one on current form.

"Guys my big sister just broke a world record! We're very excited!" tweeted Bronte Campbell.

A strong showing in Brazil would be a major turnaround for the squad, which produced just one gold at the 2012 London Olympics in a campaign marred by ill-discipline, drug use and drunkenness.

With just over a month until the Rio Games begin, the Australian Olympic Committee (AOC) applauded Campbell's form.

"Sensational! Congratulations @catecamp what a year to break the World Record," the AOC tweeted.

Campbell insisted she wouldn't be resting on her laurels ahead of Rio.

"I swim best when I think of myself as the underdog," she joked.