Incheon, Oct 3 (IANS): Indian athlete Manju Bala's hammer throw bronze won at the Asian Games Sep 28 was Friday upgraded to silver after China's Zhang Wenxiu was stripped of the gold after failing a pre-competition dope test.

A sample taken from Zhang Sep 26 was found to contain banned substances Zeranol and its metabolite. Zeranol is approved for use as a growth promoter in livestock, reports Xinhua.

"The competitor has been disqualified from the competition as well as these Games and as such her accreditation cancelled, and gold medal was withdrawn," said an Olympic Council of Asia (OCA) statement.

Zhang set a new Asiad record with a farthest throw of 77.33 metres which earned her the gold. Her compatriot Wang Zheng, who threw a best of 74.16m, will now be awarded the yellow metal while Manju's throw of 60.47m will upgrade her bronze to a silver.

Japan's Aya Masumi, who finished fourth with a throw of 59.84m, will be awarded the bronze.

The 28-year-old Zhang becomes the first Chinese athlete to be caught doping in major sporting events since the 1994 Hiroshima Asian Games where a number of positive cases involving Chinese swimmers were reported.

The Chinese Olympic Committee (COC) said that although the cause of Zhang's positive result is unknown yet, they fully respect the OCA's decision.

"The athlete may dope deliberately but there also remain the possibilities that the positive reading was due to her consumption of contaminated meat," the COC said in a statement.

"Whatever the cause is, we respect the OCA's decision regarding Zhang's case because the World Anti-Doping Code stipulates that athletes must bear the subsequences for the substance found in his or her body."

So far six athletes have failed doping tests at the 2014 Asiad and been expelled since the Games started.