UCI-ADT 2023 UCI vs Toon Aerts

In February 2022 the International Cycling Union (UCI) reported an anti-doping rule violation against the Belgian cyclist Toon Aerts after his A and B samples tested positive for the prohibited substance Letrozole.

Following notification a provisional suspension was ordered. The Athlete filed a statement in his defence and he was heard for the UCI Anti-Doping Tribunal (UCI-ADT).

The Athlete accepted the test results and denied the intentional use of the substance. He argued that there were sufficient grounds for a reduced sanction.

With evidence the Athlete made the following assertions:

  • an expert opinion report concluded that a contaminated supplement Trisport Pharma Recup Shake Choco was the source of the positive test;
  • an analysis report from an University Hospital Laboratory had detected low concentrations of Letrozole in the Athlete's supplement;
  • a hair test analysis report determined only 1 incidental minute exposure of Letrozole;
  • only through the contaminated supplement the Letrozole had entered his system;
  • other options were excluded on how the substance had entered his system.

Hereafter 1 open package of the Athlete's supplement and 3 sealed packages of the same batch were analysed in the Cologne Laboratory in August 2022. Thereupon in September 2022 the Ghent Laboratory analysed another 2 sealed packages of the same batch.

However both laboratories reported that Letrozole had not been detected in the supplement. The same open package of the supplement, analysed in the Cologne Laboratory, had previously been analysed in the University Hospital Laboratory.

In this case the Parties both agree that the current file does not contain any element from which one can deduce that the violation was committed intentionally. Nevertheless the UCI raised the following objections:

  • There is no reliable or concrete evidence that the Athlete's supplement was contaminated;
  • The report of the University Hospital Laboratory is unreliable;
  • The Cologne and Ghent laboratories detected no Letrozole in the supplement;
  • The Cologne Laboratory is more performant than de University Hospital Laboratory and has a lower limit of detection;
  • Previous collected samples tested negative in the period that the supplement had been used by the Athlete;
  • No other members of the Athlete's team tested positive after using this supplement at the material time;
  • The hairtest does not reveal the source of Letrozole;
  • The alleged low concentration found by the University Hospital Laboratory in the Athlete's supplement is not consistent with the concentration Letrozole detected in the Athlete's sample.

The Sole Arbitrator assessed and addressed the evidence and assertions of the Parties and their expert witnesses. Ultimately the Arbitrator concludes that the Athlete has not discharged his burden of proof how, on a balance of probability, the prohibited substance had entered his system.

Therefore the UCI Anti-Doping Panel decides on 16 August 2023 to impose a 2 year period of ineligibility on the Athlete, starting on the date of the provisional suspension, i.e. on 16 February 2022.

The Athlete shall be borne:

  • The UCI legal costs;
  • The costs for the results management;
  • The costs of the out-of-competition testing; and
  • The costs of the analyses of the supplement by the Cologne Laboratory.

Original document


Legal Source
Decisions International Federations
16 August 2023
Haas, Ulrich
Original Source
International Cycling Union (UCI)
Adverse Analytical Finding / presence
Legal Terms
Burdens and standards of proof
Case law / jurisprudence
Circumstantial evidence
No intention to enhance performance
Period of ineligibility
Principle of fairness
Sole Arbitrator
Cycling (UCI) - International Cycling Union
Cologne, Germany: Institute of Biochemistry - German Sport University Cologne
Ghent, Belgium: DoCoLab Universiteit Gent-UGent
Analytical aspects
B sample analysis
Doping classes
S4. Hormone And Metabolic Modulators
Disqualified competition results
Document type
Pdf file
Date generated
11 October 2023
Date of last modification
30 October 2023
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