A diplomatic storm was brewing last night over Olympic swimming sensation Ye Shiwen.

The Chinese 16-year-old was forced to deny using drugs after a respected US coach called her gold medal-winning performance ‘unbelievable’.

But her defiant pledge that the world record-breaking swim on Saturday – which saw her outpace the winner of the men’s event – came purely from ‘hard work and training’ failed to defuse a doping controversy gripping London 2012.

John Leonard, the US executive director of the World Swimming Coaches Association, described Saturday’s swim by ‘Supergirl’ Miss Ye – who last night broke the Olympic record in another event – as ‘unbelievable’ and ‘disturbing’.

He also made the extraordinary suggestion that the Chinese could be using genetic manipulation to enhance performances.

His claims came as anti-doping officials revealed that cleaners and security staff have been asked to spy on athletes in the Olympic Village and report anything suspicious that could be linked to performance-enhancing drugs.But Mr Leonard compared the final 100m swum by Miss Ye as being ‘reminiscent’ of some old East German swimmers, several of whom were subsequently exposed for using performance-enhancing drugs.

Pressed on the use of drugs she told the China News Service last night: ‘There is absolutely no problem with doping. The Chinese have always had a firm policy about doping. My results come from hard work and training and I would never use any banned drugs. The Chinese people have clean hands.’

As a gold medal winner, Miss Ye will have been automatically drug-tested. The first four in each race are routinely tested.

【新闻快讯】

自从打破女子400米混合泳世界纪录后，中国小将叶诗文这几日除了收到各方的祝福外，她的神奇速度也遭到外媒过度“询问”，30日她在新闻发布会上表示，“我的成绩来源于勤奋和训练，不会使用任何禁药，中国人是清白的。”

查阅这几日的世界主流媒体，对于中国人在伦敦泳池中掀起的“巨浪”颇为惊叹，他们不解为什么中国选手突破如此之快，到底什么原因造就了孙杨和叶诗文。就连中国记者也成了他们的采访对象，他们渴望了解中国运动员的一切，例如祖籍、生活习惯、训练方式以及有没有男女朋友.……

30日上午的女子200米个人混合泳预赛，因为叶诗文的参赛，这个项目成了各国记者最关注的焦点。早些完成比赛的菲尔普斯则沦为“配角”，他只被记者问了三个问题就草草收场，而对叶诗文的提问，则多达数十个。

有美联社记者问，“你的成绩为什么快？”叶诗文平静地说，“可能是之前的训练比较好，体能储备充足，加上对奥运会的渴望，让我超越了自己的极限。”

“那你可以谈谈自己的生活吗？”

“你的人生除了游泳还有什么？”

“你在海外训练得到了什么？”

记者铺天盖地追问，让叶诗文有些应接不暇，“其实我很普通，我有自己的生活方式，例如训练之外，可能会看电视，听音乐，出去玩，干一些喜欢的事。”

“尤其在澳大利亚训练对我的体能和训练方式有很大帮助，例如出发以及转身等，”叶诗文说，“本来喜欢这个项目，很热爱，所以挺享受‘苦中作乐’的。”

这位美联社记者还问道，“中国运动员90年代出现过使用兴奋剂的问题，对于你这个十几岁的小女孩一下子打破世界纪录，人们都在怀疑，你怎么回应？”

叶诗文直视对方说，“我们的运动员只坚信一点，坚决反对兴奋剂，坚决不用兴奋剂。”

她还请中国记者转告给外国同行，“我想让他们‘放心’，中国人是清白的。”