China, the dominant force in world diving for the best part of 20 years, won six out of eight Olympic titles in Athens and prompted speculation about a clean sweep when they stage the Games in Beijing in 2008.

The rest of the world dented China's superiority at the 2003 world championships in Barcelona by restricting the number one nation to four out of 10 titles after China had claimed eight of 10 in 2001.

But having taken five of eight Olympic crowns at the 2000 Sydney Games, China made it six in Athens as world champion Guo Jingjing won the women's three-metre springboard; Peng Bo, the men's springboard, and Hu Jia, the men's platform and Chinese pairs collected three of the four synchronised diving titles.

In the 1980s it was chiefly American Greg Louganis who denied the Chinese, winning platform and springboard golds at both the 1984 and 1988 Olympics.

In the 1990s, after American Mark Lenzi had taken the 1992 Olympic springboard gold, it often seemed that Russian iron man Dmitry Sautin was waging a one-man battle against Chinese domination.

Among a succession of Chinese champions, Fu Mingxia, a world champion at 12, was outstanding and carried off two Olympic platform and two springboard golds in the three Olympics from 1992 to 2000.

China have won 20 Olympic titles out of 32 in the last 20 years since Zhao Jihong gained the nation's first in the women's platform at the 1984 Los Angeles Games.

So, why are they so good?

"I just think the training that they do is very intense," said Australia's Mathew Helm, who denied the Chinese a one-two in the concluding men's platform final on Saturday when he split Hu and defending champion Tian Liang to take the silver.

Is a Chinese title sweep possible in Beijing?

"It's possible and up until a year or two years ago they just completely dominated the sport," Helm said.

But he noted that Chantelle Newbery had won the women's platform in Athens and her husband Robert and himself won the men's synchronised platform at the 2003 world championships.

"So they are beatable and it's now that we've started to realise that. But they are amazing athletes," Helm said.

Tian said he had felt under pressure to repeat his Sydney title feat but hoped to have another shot in 2008. "For Beijing we will do our best to get eight gold medals but nobody can guarantee that, we can only try our best," he said.