Who is to Blame in Jannik Sinner's Doping Scandal?

When tennis star Jannik Sinner tested positive for a banned substance, he blamed contamination—but under strict liability, intent doesn’t matter. WADA is taking up this fight at the CAS.

By Pauline Mbanza. This article was first published by the Gujarat National Law University’s Centre for Sports and Entertainment Law. It has been lightly edited for flow. Its views do not necessarily represent those of The Sports and Crime Briefing.

When Tom Hicks won the marathon at the 1904 Summer Olympics, he collapsed due to a mixture of brandy and strychnine in his system. His team had fed these to him as he was showing signs of tiredness due to the competition. Yet it would take decades for the IOC to ban the substance, as part of its early anti-doping efforts in the 1960s. The first doping tests for conventional substances were held at the 1972 Olympic Games in Munich, while anabolic substances were banned in Montreal in 1976. The latter also saw athletes’ test results being made public and the introduction of bans. This progress continued with the creation of WADA in 1999.

Yet, despite this progress, a blame game often arises when an athlete tests positive.

The Case of Jannik Sinner

In March 2024, rising tennis star Jannik Sinner tested positive for clostebol, a banned substance derived from testosterone. His first sample was collected on March 10 during a tournament at Indian Wells tournament, and a second sample was taken on March 18 during an out-of-competition test in Miami—both tested positive. The detected amount was minuscule, less than a billionth of a gram. On April 4, Sinner was officially informed of the results and issued a provisional suspension from competition. He immediately appealed the decision and faced a brief provisional ban between April 17 and April 20, 2024.

In August, the International Tennis Integrity Agency opened a doping case against Sinner. During this case, Sinner argued that his tests came out positive due to contamination, a valid defense in doping cases. However, he claimed to be unaware that his physiotherapist had treated him with Trofodermin, a common medical cream used to treat wounds. Sinner’s defense was accepted by the International Tennis Integrity Agency tribunal and his ban was lifted, after experts claiming his defense was plausible.

However, the World Anti-Doping Agency (WADA) has appealed this decision to the Court of Arbitration for Sport (CAS), seeking to overturn the ITIA's ruling. WADA argues that Sinner committed two Anti-Doping Rule Violations (ADRVs) under Articles 2.1 and 2.2 of the Tennis Anti-Doping Programme (TADP) and that Article 10.5, which allows for reduced sanctions in cases of no significant fault or negligence, should not apply. WADA is pushing for a one- to two-year period of ineligibility for Sinner, along with the disqualification of all results obtained during the BNP Paribas Open in Indian Wells.

Why is WADA Appealing to CAS?

Since the campaign against doping began, several measures have been implemented to prevent athletes from artificially enhancing their performance. In the modern era, where advancements in doping technology often outpace regulation, authorities have had to adopt stringent measures, including the principle of strict liability. This legal doctrine holds athletes fully responsible for any substance found in their bodies, regardless of intent. If a banned substance is detected, the athlete is automatically liable and may face consequences such as a sporting ban.

A notable example is that of football player Paul Pogba, whose ban was reduced from four years to 18 months in 2024, after he argued that a doctor had unknowingly given him testosterone-boosting supplements.

The purpose of this principle is to deter doping and ensure athletes remain vigilant about what they consume or come into contact with. Without strict liability, athletes could claim ignorance or negligence, undermining anti-doping efforts.

In Sinner’s case, WADA is applying the same strict liability approach used in Pogba’s case. The agency argues that regardless of whether Sinner was aware of the contamination, he is responsible for ensuring that his physiotherapist did not expose him to banned substances. Under Articles 2.1 and 2.2 of the Tennis Anti-Doping Programme (TADP), athletes are prohibited from using banned substances unless granted a Therapeutic Use Exemption (TUE). These articles reinforce strict liability, meaning that unless an athlete has a valid TUE, they are fully responsible for any prohibited substances found in their body.

Strict liability ensures that athletes take full responsibility for their actions and environment. While TUEs provide exemptions for medical needs, they do not override the principle that an athlete is accountable for any banned substances detected in their body. Even in cases of contamination or due diligence, athletes often still face bans, as seen in Pogba’s case.

These articles implicitly provide for strict liability, except in cases where a TUE is granted. A TUE allows athletes to use specific substances that may otherwise be prohibited if they are deemed necessary for their health. However, without a valid TUE, an athlete has no grounds to contest a positive test result.

WADA is insisting that strict liability be applied in Sinner’s case, as it has been in similar cases before. Sinner acknowledges that his samples tested positive but claims contamination beyond his control. However, under anti-doping regulations, he remains responsible for monitoring what enters his body at all times. Consequently, WADA argues that he must face a sporting ban without the application of Article 10.5 of the TADP, which allows for reduced sanctions only if a valid TUE is in place. The enforcement of strict liability means that any athlete who tests positive for a banned substance is automatically held accountable, even in cases where TUEs may reduce or eliminate penalties.

The strict enforcement of this principle aims to ensure that, even as doping methods continue to evolve, athletes remain deterred from enhancing their performance artificially and are held to the highest anti-doping standards.