The president of the Croatian Tennis Federation says he ‘deeply believes’ one of his country’s top players unintentionally consumed a banned substance after she was issued with a provisional suspension.
Jana Fett, who has been ranked as high as 97th in the world, failed an anti-doping test last year during a play-off tie at the Billie Jean King Cup, which was being held in her home country. After the testing of her A and B samples, the International Tennis Integrity Agency issued a statement announcing three banned substances had been detected. One of those was discontinued in 2007 following medical research which found a link to a rapid increase in cancer when testing it on rats.
The ITIA listed the banned substances detected as muscle stimulant ostarine, LGD-4033, which helps increase lean muscle, and GW501516v (GW1516). The last substance is the one that was discontinued over its links to cancer.
“The substances are prohibited under the TADP in the categories of Other Anabolic Agents (Section S1.2) and Metabolic Modulators (Section S4.4) of the 2025 Prohibited List,” the ITIA said in a statement.
“As two of the substances are non-Specified substances, a mandatory provisional suspension is required. In Fett’s case this has been in effect from 22 December 2025.
“Players have the right to appeal the imposition of their provisional suspension before an independent tribunal chair. To date, Fett has not appealed.
“While provisionally suspended, Fett is prohibited from playing in, coaching at, or attending any tennis event authorised or sanctioned by the members of the ITIA or any national association.”
29-year-old Fett is currently her country’s fourth-highest-ranked singles player at 189th in the world. She has played in five Grand Slam main draws during her career, reaching the second round at the 2018 Australian Open and 2024 French Open. She has won 10 ITF titles, with the most prestigious being the 2024 Oeiras Open, which was a W100 event.
The tennis player is yet to speak publicly about her suspension from the Tour. However, Croatia’s tennis federation has issued a statement in support of Fett.
“We can confirm that we have been notified of a positive doping finding for our national team player Jana Fett, based on a sample taken during Croatia’s appearance at the Billie Jean King Cup in Varaždin last November,” Croatian Tennis Federation President Zdravko Marić said in a statement posted on their website.
“At this time, this is all we know about the situation. Knowing Jana as an extremely fair athlete, I deeply believe that she ingested the prohibited substance unintentionally, and not with the goal of gaining a sporting advantage over the rules. We will be in contact with Jana and the ITA.”
Fett hasn’t played on the Tour since the first week of December, when she lost in the quarter-finals of an ITF event in Italy.
