There's been a lot of chin-stroking about the fantastic performance Saturday from Ye Shiwen, a 16-year-old Chinese swimmer who set a new record for the female medley.

Ye set an fantastic world record of 4 minutes 28.43 seconds. Incredibly, over the last 50 meters she swam faster than Ryan Lochte did in the same event — even though Lochte set the second fastest men's time in history. Li wasn't even a favorite in the race.

Top US Coach John Leonard, who is the executive director of the World Swimming Coaches Association, has become the first high-profile person in coaching to openly mention the "d-word", though he did so with some caveats. He told the Guardian today:

"We want to be very careful about calling it doping [...] The one thing I will say is that history in our sport will tell you that every time we see something, and I will put quotation marks around this, 'unbelievable', history shows us that it turns out later on there was doping involved. That last 100m was reminiscent of some old East German swimmers, for people who have been around a while. It was reminiscent of 400m individual medley by a young Irish woman in Atlanta."

(Leonard is referring to the widespread use of performance enhancing drugs by East German swimmers, and the case of Michelle Smith, an Irish swimmer who had an incredibly successful run in the 1996 Atlanta games but left the sport after a subsequent doping ban).

Leonard's skepticism isn't backed up by other high profile officials. Ame Ljungqvist, medical chief of the IOC, addressed the doping theories today in a press conference, and said he had no suspicions.

Lochte himself seems to not be worried about the comparison. "We were all talking about that at dinner last night," he said, according to Yahoo! Sports. "It was pretty impressive. And it was a female. She's fast. If she was there with me, I don't know, she might have beat me."

The New York Times reports China had at least 50 athletes test positive for illegal substances in the 1980s and 1990s. Chinese sporting authorities are said to be extra-vigilant about testing in order to avoid more embarrassment for the country.