According to our statistics 33 US athletes has been sanctioned which is more than the double of UK which comes in second with 15 contamination related cases. Brazil has sanctioned 14 athletes. China is the last item on our top ten list with just six cases – the same. As Ireland and Austria.
Equestrian is the sport in the US where most of the contamination cases has happened. Six athletes in this sport has been sanctioned. Weightlifting and athletics comes in second with four each. For cycling we have registered three cases related to contamination. Swimming and triathlon both have two registered doping sanction in our database related to contamination.
Trimetazidine found in 23 Chinese samples – all cleared
The German broadcaster ARD aired a documentary in 2024 which showed that 23 Chinese swimmers had been cleared after testing positive for a prohibited substance. Reason: Contaminated food.
Between 1 and 3 January 2021, the China Anti-Doping Agency (CHINADA) collected 60 urine samples of Chinese swimmers at a national swimming meet where 201 swimmers competing.
The samples were analysed at the WADA-accreditated laboratory in Beijing. The laboratory reported 28 adverse analytical findings for the prohibited substance trimetazidine.
There were 23 swimmers who tested positive, which means a small number of them tested positive more than once.
Four athletes from different sports tests positive after posible contamination
The World Anti-Doping Agency (WADA) was notified on June 2021 of the decision by the China Anti-Doping Agency (CHINADA) to accept that the swimmers had tested positive for the banned substance after inadvertently being exposed to the substance through contamination.
Since the swimming cases WADA has also published four athletes (two swimmers, one shooter and one BMX rider). All the athletes tested positive for methandienone in late 2022 and early 2023.
Following its investigation, CHINADA concluded that the four cases were most likely linked to meat contamination and, in late 2023, closed the cases without asserting a violation, with the athletes having remained provisionally suspended throughout that time, writes WADA on their website.
As a result of the last four positive tests, WADA initiated an investigation in early 2024 to find the scale and risk of meat contamination with methandienone in China and other countries.
Trenbolone found in food – US sprinter cleared
In March 2024 Erriyon Knighton was tested out-of-competition at his home in Gainesville in Florida. The sample was sent to the WADA-accredited laboratory in Salt Lake City in the state of Utah. The laboratory reported an adverse analytical finding for epitrenbolone – the main metabolite of trenbolone.
Knighton was at the time ranked second in the world in the 200 meters sprint. He also had represented Team USA at the Olympic Games in Tokyo three years prior (2021). The American sprinter won silver at the World Championships in 2023.
In his defense, according to the legal papers found on the USADA website, Knighton believes his positive test was caused by consuming oxtail from a local restaurant in Brandon, Florida. The USADA interviewed the owner of the restaurant and the distributor of the oxtail. The distributor explained that they buy oxtail from a supplier based in Mexico. Shipment packaging showed that the extail from the distributor actually came from Nicaragua.
The USADA obtained a sample of oxtail and had this analysed at the WADA-accreditated laboratory at UCLA. The analysis found traces of trenbolone at a concentration of 0.1ng/g.
Trenbolone is banned in EU, but is used in both USA and the majority of South and Central American countries.
Erriyon Knighton was cleared of any anti-doping rule violation. He was part of the Team USA who competed at the Paris Oympic Games in July and August 2024.
Boldenone found in food – US wrestler cleared
In 2021 the American wrestler Nathan Dyamin Jackson traveled to Guatemala to compete at the Pan American Championships. The wrestler won the 92kg weight class and was selected for doping test.
The analysis done at the WADA-accredited laboratory in Montreal, Canada, showed traces of the steroid boldenone.
Jackson asked for the B-sample to be analysed. At the same time the International Testing Agency obtained the menu from the Hotel Conquistador which indicated the food that was served on the days that the athlete was staying there with his team.
According to the legal papers from the hearing of Jackson, it is well known that boldenone is widely used in Guatemalan livestock, including poultry.
Jackson was cleared from the sanction based on evidence.
Contador and the meat contamination claim
In 2010, during the Tour de France, the spanish cyclist Alberto Contador tested positive for the steroid Clenbuterol. Reason: Contaminated food.
Contador was the winner of the Grand Tour race that year.
According to a statement from the International Cycling Union (ICU) the concentration of the banned substance was 50 picograms, 400 times less than the threshold required by a World Anti-Doping Agency accredited laboratory. Contador was still suspended for two years. The spanish pro-cyclist said in his defense that he ate meat during the rest days in the Tour. The meat had been brought across the border from Spain to France.
Contador was sanctioned for two years. He was also disqualified from the Tour.
Jessica Hardy and the supplement contamination case
In 2008 the US swimmer Jessica Hardy was tested after the 2008 US Olympic Team Trials. Hardy was one of the contenders to qualify for the Beijing Olympic Summer Games that same year.
The analysis showed traces of Clenbuterol, the same substance Contador tested positive for. The difference in the two cases was that the banned substance was believed to come from a contaminated supplement. Athletes has for long been warned that supplements may contain banned substances – either by accident or deliberate.
Hardy was given a one year suspension. She did not compete at the Games in China.
Double standards?
Since the publication of the 23 Chinese cleared swimmers and the clearence of the US sprinters, both countries has gone more or less head to head.
China claims US has double standards where they on one hand cleares their one of their favorites to win 200 meters at the Olympic Games and at the same time critizises China for not playing fair with their swimmers.
WADA says it has “unfairly caught” in a row between the US and China. US claims WADA was covering up the Chinese positive cases.
WADA writes on their website:
“The politicization of anti-doping continues with this latest attempt by the media in the United States to imply wrongdoing on the part of WADA and the broader anti-doping community. As we have seen over recent months, WADA has been unfairly caught in the middle of geopolitical tensions between superpowers but has no mandate to participate in that.”
Sources:
China:
https://www.wada-ama.org/en/news/wada-statement-case-23-swimmers-china
https://www.wada-ama.org/en/key-documents-regarding-chinese-swimming-case
Knighton:
Decision: https://www.usada.org/wp-content/uploads/Knighton-Operative-Award.pdf
Jackson:
CAS decision: https://jurisprudence.tas-cas.org/Shared%20Documents/ADD%2046.pdf
Contador
https://www.cyclingnews.com/news/contadors-contaminated-food-excuse-or-possibility/
https://www.theguardian.com/sport/2010/sep/30/alberto-contador-positive-test