Sixteen-year-old Chinese swimming prodigy Ye Shiwen categorically denied doping on Monday after British media raised suspicions about her world record-breaking start to the London Olympics.

Ye shattered Stephanie Rice's mark in the women's 400m individual medley by more than a second, including an astonishing final lap which was faster than US winner Ryan Lochte and Michael Phelps in the men's competition.

"Insane," commented Rice. "I mean I didn't see it, I was way over and behind, so I didn't really see her coming home, but that split coming home was out of control, faster than everyone but Phelps I think."

With the swim, Ye took nearly seven seconds off her time at last year's world championships.

And she was lightning quick in Monday's 200m medley heats, timing more than a second-and-a-half faster than the rest of the field for the quickest time this year.

China's Ye Shiwen displays her gold medal after her stunning 400m individual medley swim at the London 2012 Olympics on July 28. The sixteen-year-old swimming prodigy categorically denied doping on Monday after British media raised suspicions about her world record-breaking start to the London Olympics.

But the Zhejiang youngster, who announced herself on the global stage with the 200m medley world title last year, said there was nothing untoward.

"There is no problem with doping, the Chinese team has a firm policy so there is no problem with that," she said.

Ye was put on the spot after leading British newspapers pounced on her performances, pointing to China's record of state-sponsored doping in the 1980s and 1990s.

"Ye's amazing time for freestyle leg scarcely credible," said a headline in The Times, which said Li Zhesi, also 16, and who was barred from the Olympics in June over blood-booster EPO, was Ye's training partner.

"Chinese swimming has such a shameful history of doping that any remarkable achievement by one of its athletes is inevitably met with cynicism," commented the Daily Telegraph.