Ngo Thi Hang, who won three gold medals in the women's 75kg weightlifting category at Vietnam's National Physical Training and Sports Championships in December 2010, has tested positive for banned substances.
According to a report from China's Doping Control Center, Hanh tested positive for a banned substance called Methandienone, a substance that can improve athletes' performance.
This is really bad news for the country's sports in general and weightlifting in particular, after another leading national weightlifter, Hoang Anh Tuan, failed doping tests last year.
Tuan, who won the men's 56kg silver medal at the 2008 Olympics in China, tested positive to banned substances at the World Weightlifting Championships in Turkey in 2010.
The World Weightlifting Federation last month decided to suspend Tuan for two years and fine him US$5,000.
Hang could also face a suspension penalty after the latest finding.