The Taiwanese weightlifter was informed last year that she had tested positive for a banned substance, but the news was not made public until this week.
Two-time Olympic gold medalist Hsu Shu-ching apologised Friday for testing positive for doping and said she is willing to accept her punishment.
The Taiwanese weightlifter was told of the result last year but the news was not made public until this week.
The 27-year-old Hsu said the banned substance was contained in a dietary supplement she took ahead of the 2017 world championships.
Hsu, who retired from the sport last year citing injuries, returned a silver medal she won at the championships and resigned a coaching position. It was unclear what punishment she could face.
Tseng Wen-hung, a liaison officer with Taiwan's Olympic Committee, said Hsu "couldn't participate in relevant work or competitions."
Hsu won gold in the 53-kilogram class at the 2012 London Olympics, after the original winner, Zulfiya Chinshanlo, failed a doping retest.
She also won gold at the 2016 Games in Rio de Janeiro.
Chronic problems with doping are threatening weightlifting's future viability as an Olympic sport, particularly one that offered opportunities for competitors from countries such as Taiwan that are rarely able to compete with sports powerhouses such as the United States, Russia and China.