SEVILLE, Spain (AFP) - Australian Olympic champion Grant Hackett failed to secure a berth for the Beijing Olympics' 10km open water event when he was disqualified from the 10km race at the world championships here Sunday.

The event was won by Russian Vladimir Dyatchin in a time of 1hr 53min 21sec, ahead of Britain's David Davies, who finished a close three tenths of a second behind.

Another Australian, Ky Hurst, who tied for fifth place at 16.6sec behind Dyatchin, secured his Olympic ticket for Beijing.

Hackett won gold in the 1500 metres at both the Sydney 2000 and Athens 2004 Olympics and is one of the big favourites to go for a rare triple in Beijing.

However his dream of winning gold in both rough and still water was torpedoed Sunday when he failed to finish with the top ten place that would have taken him to the Beijing open water competition.

Hackett finished 15th and said he had been targeted by aggressive opponents.

But he was then dramatically disqualified because the race referee ruled he had caused interference with other swimmers.

"It certainly surprised me, that's for sure," Hackett said.

"I knew it was going to be a rough race, and there was plenty of guys pulling legs, swimming over the top of each other around the turning buoys, but I was determined to stay away from all that kind of stuff.

"There were times when there were bodies everywhere. With 150m to go, another swimmer swam over the top of me and pulled me back, and I swam over his legs - and that's what I was supposedly disqualified for."