China's former world champion Qian Chen has been suspended by the International Modern Pentathlon Union (UIPM) for four years after testing positive for banned performance-enhancing drugs at last year's Olympic Games in Rio de Janeiro.
The ban was imposed after the 30-year-old Chen lost an appeal at the Court of Arbitration for Sport.
Chen had already been stripped of her fourth place finish at Rio 2016 following the positive drugs test for the diuretic hydrochlorothiazide.
The product is included on the World Anti-Doping Agency (WADA) prohibited list due to its possible use as a masking agent.
The UIPM Doping Review Panel invited Qian Chen to take part in a process of hearing and adjudication. The panel concluded that the athlete had provided no evidence of mitigating circumstances and imposed a four-year period of ineligibility dated from August 22, 2016.
"The UIPM Doping Review Panel invited Qian Chen to take part in a process of hearing and adjudication," the world governing body said.
"The Panel concluded that the athlete had provided no evidence of mitigating circumstances and imposed a four-year period of ineligibility dated from August 22, 2016."
Having been informed of the decision, Chen told the UIPM she was retiring from the sport.
Chen's most notable achievement was winning the individual title at the 2009 World Championships in London.
She also won gold medals in the relay at the World Championships in Warsaw in 2014 and Berlin in 2015.
They were among nine World Championships she won during her career.
Chen never, however, managed to win a medal in the Olympics, finishing fifth at both Beijing 2008 and London 2012.
The first-ever athlete to be banned for drugs at the Olympic Games came in modern pentathlon.
Sweden's Hans-Grunner Liljenwall was disqualified at Mexico City 1968 for for alcohol use.
He reportedly had "two beers" to calm his nerves before the pistol shooting event.
The Swedish team eventually had to return their bronze medals.