Ian Thorpe, who was disqualified at the trials, in Sydney on Saturday

Sydney: Olympic champion Ian Thorpe will not be defending his 400 m freestyle title at this year’s Athens Olympics after a sensational disqualification at the Australian Olympic swimming trials here Saturday.

Thorpe lost his chance to swim in the event at the Summer Games in August after a protest at his disqualification for a false start was dismissed.

The 21-year-old swimming great overbalanced on the starting blocks and fell into the water before the official start of his morning heat on a dramatic opening day of the eight-day selection trials at the Sydney Olympic pool.

He got out of the pool and returned to the blocks with the rest of the competitors.

But meet referee John Keppie walked over to Thorpe’s number four lane and disqualified him to audible gasps from the small crowd.

Thorpe looked stunned at the realisation of what it all meant as he walked off the pool deck.

Thorpe appealed the decision but it was rejected, robbing the world swimming superstar of his chance to grab gold in the event he has dominated since 1999.

His manager Dave Flaskas said the Olympic, world and Commonwealth champion apparently heard a noise before he fell into the water. But meet officials decided at a subsequent appeal hearing and after viewing television footage of the incident, that they could not overturn the disqualification.

Under Australian swimming’s strict Olympic selection policy, only the first two place getters at the trials in individual events are eligible to compete in those races at the Games.

Thorpe has dominated world 400m freestyle swimming since becoming the youngest male world champion as a 15-year-old at the 1998 Perth titles.

He has held the world 400m record since August, 1999, where he first set it at the Pan Pacific championships in the same Sydney pool. Thorpe has since broken the world record another four times, the last time at the 2002 Manchester Commonwealth Games in three minutes 40.08 seconds.

In Thorpe’s absence, Grant Hackett qualified fastest for the 400m final in 3:46.09 ahead of Craig Stevens and Ky Hurst.