Chinese swimmer Chen Xinyi has been given a two-year doping ban ©Getty Images

Chinese swimmer Chen Xinyi has been given a two-year doping ban by the International Swimming Federation (FINA) after she tested positive for a banned substance at the Olympic Games in Rio de Janeiro.

Chen was the first athlete to fail an in-competition drugs test at the event in the Brazilian city when the 18-year-old returned a positive test for diuretic hydrochlorothiazide after missing out on a bronze medal by just nine hundredths of a second in the women’s 100 metres butterfly final on the second day of the Games on August 6.

The case was confirmed by the Court of Arbitration for Sport.

The two-time Incheon 2014 Asian Games gold medallist applied to the International Olympic Committee to have her B-sample opened, news agency Xinhua had reported, but she then failed to start her scheduled 50m freestyle heat on August 12.

Although not directly performance-enhancing, diuretics are banned because of their use as masking agents to hide the presence of other products.

FINA confirmed Chen's suspension, which rules her out of next year's World Championships in Budapest, a candidate city for the 2024 Olympic and Paralympic Games, will end on August 10, 2018.

“On 8 August 2016, the International Olympic Committee conducted a doping control test during the Rio 2016 Olympic Games on the swimmer Xinyi Chen,” FINA said in a statement.

Chen Xinyi tested positive at the Rio 2016 Olympic Games ©Getty Images
Chen Xinyi tested positive at the Rio 2016 Olympic Games ©Getty Images

“The athlete was tested positive to the substance Hydrochlorothiazide (Class S5 of the WADA Prohibited List 2016, Diuretics and Masking Agents).

“The FINA Doping Panel decided according to the FINA DC Rule DC 10.2.2 to impose on the athlete a period of two years’ ineligibility, starting on 11 August 2016 and ending on 10 August 2018 for her first anti-doping rule violation.

“Furthermore, the FINA Doping Panel acknowledged the Court of Arbitration for Sport (CAS) Panel decision regarding the disqualification of the athlete’s results at the Rio 2016 Olympic Games.”

Chinese swimming was thrust under the microscope in the build-up to Rio 2016 following claims that doping tests were covered up in the sport in the nation.

The World Anti-Doping Agency (WADA) launched an investigation after The Times reported a total of five Chinese swimmers tested positive, with two coming in October and three at the turn of the year.

These results were concealed and covered-up, the reports claim.

They also accused swimming coach Zhou Ming, who was banned for life in 1998 for involvement in a previous doping scheme in the sport in China, of working with swimmers in Tianjin.