Chinese swimmer Ye Shiwen ignores drugs claims to seize her second gold of London 2012

China's 16-year-old star insists she is unaffected by accusations that she must be a doper

After winning her second gold medal, Ye Shiwen last night denied she was a doper and suggested there is a bias against her and China. The 16-year-old added the 200m individual medley crown to Saturday's dramatic success to make it two golds from two swims in the multi-discipline events.

The schoolgirl from Zhejiang province became the closest watched competitor in the London Olympics after three days of swirling speculation over the veracity of her jaw-dropping performance on the first finals night. That produced a world record and one gathered at such a dramatic pace that it has prompted open accusations that all is not as it should be; in short, it has been suggested, she is a doper.

After her victory, Ye faced the world's media and asked whether she had ever taken performing enhancing substances or any other form of doping replied "absolutely not".

"They are biased," she said of her accusers to applause from a Chinese journalist. "In other countries there are swimmers that have won many medals and nobody questions them. How come people will criticise me because I have won two?"

Her denials follow that of China's Olympic authorities and she has not returned a positive test. As a medallist she is automatically tested. When she was introduced to the crowd before her race the reception was not noticeably cool and nor was it when she stepped on to the podium half an hour later to collect her gold. There was certainly no booing.

"It's okay, it didn't affect me," said Ye on the storm that has surrounded her. Last night was her main event, the 200m individual medley at which she is already the world champion. Ye, who has been training since the age of seven, is now the Olympic champion as well but this was far from the procession predicted after she eased to a new Games record in the morning heats.

In the 400m it was her last freestyle leg that destroyed the field, an acceleration that left the pre-Games favourite Elizabeth Beisel floundering. She finished faster than Ryan Lochte. Last night she finished strongly, her freestyle possesses incredible power and it was too much for Australia's Alicia Coutts and Caitlin Leverenz of the US.

Ye won by just under a second but that margin was only earned over the closing metres. The time of 2 min 07.57 sec was 0.82 better than her Olympic record from the heats but nearly one and a half seconds short of the world record set by Ariana Kukors, who finished fifth last night. Kukors high-water mark was set at the peak of the body suit era.

And one final figure; Ye covered her final 50m, the freestyle leg, in 29.32 seconds. Last night Lochte completed the final 50m of his leg of the 200m freestyle relay in 26.2sec.

Hannah Miley finished seventh to add to her fifth place in the 400m IM on Saturday. It was an encouraging night for the host nation, led by the two men's breaststrokers Michael Jamieson and Andrew Willis as they qualified first and third fastest for tonight's 200m breaststroke final

Jamieson took his place in style, breaking the British record for the second time in the day. The 23-year-old Glaswegian had done so in the morning heats and last night went even quicker, touching in 2min 08.20sec. He was quickly followed into the final by Willis, who bettered the English record as he had also done in the heats. Jemma Lowe recovered from a slow start to snatch a place in tonight's final of the 200m butterfly.