The Chinese Weightlifting Association on Wednesday expressed shock over the news that three Chinese weightlifters were among 15 who have failed retesting of their samples from the 2008 Beijing Olympics.
In a statement, the associated said it will cooperate with the International Weightlifting Federation in the investigation and reiterated its stance against doping.
"If, after investigation, activities are found to have violated the rules, the association will not tolerate this, and severe punishment will be meted out," the association said.
Earlier on Wednesday, the federation posted on its website that 15 weightlifters from six countries, including 11 medalists at the 2008 Games, had failed retests of their samples.
"In line with the rules and regulations, the IWF imposed mandatory provisional suspensions upon the athletes, who remain provisionally suspended in view of potential anti-doping rule violations until their cases are closed," the federation said.
Among the lifters who tested positive include Chinese gold medallists Chen Xiexia, who won the women's 48 kg division in Beijing, Liu Chunhong, winner of the women's 69 kg, and Cao, who bagged the gold for the women's 75 kg.
All three tested positive for GHRP-2, a type of endurance-boosting hormone. Liu also tested positive for the stimulant sibutramine, according to a report from China Daily on Thursday.
If the results are confirmed, the three could be stripped of their gold medals, the report said.
The incident marks the first time Chinese weightlifters tested positive at the Olympics, and all of the Chinese lifters involved have retired.
In addition to Chinese athletes, weightlifters from Russia, Ukraine, Belarus, Azerbaijan and Kazakhstan have tested positive in the reanalysis.
After decisions taken by the International Olympic Committee, the federation took over the management of the cases.
The federation would not comment further on the cases until after they were concluded, the statement said.
China's General Administration of Sport declined to comment on the report as of press time.
China's weightlifters took home five gold medals at the Rio Olympics, which ended on Sunday.