Women’s world No 2 Iga Swiatek has been handed a one-month ban from competing after testing positive for a prohibited heart medication.

Swiatek, who has won four French Opens and a US Open, was found to have a trace concentration of trimetazidine (TMZ) in an out-of-competition sample on August 12.

But the International Tennis Integrity Agency (ITIA) ruled that the 23-year-old’s breach was unintentional and considered it at the lowest end of “No Significant Fault or Negligence”.

She had already served 22 days of the ban while the investigation process was ongoing, so she will be able to play from 4 December.

The suspension was temporarily lifted on 4 October to allow her to compete in the WTA Finals and at the Billie Jean King Cup in Malaga.

After submitting hair samples, alongside all medication and supplements she uses, to an independent laboratory, the presence of TMZ was confirmed in a melatonin supplement the Polish star uses to manage jetlag.

In her appeal, Swiatek said she had been using the product “without issue for many years”, and had first been advised to take it by her doctor in 2019.

The World Anti-Doping Agency (Wada) or the Polish domestic equivalent Polada now have 28 days to appeal the ruling to the Court of Arbitration for Sport.

TMZ is the drug at the centre of the case involving 23 Chinese swimmers who remained eligible despite testing positive for performance enhancers in 2021.

What is trimetazidine (TMZ)?

Trimetazidine, commonly known as TMZ, is used medically to treat heart conditions such as angina.

It increases blood flow to the heart and limits rapid swings in blood pressure and as such has the potential to enhance performance by helping the heart function better.

Since 2014, TMZ has been listed on the World Anti-Doping Agency (WADA) list as a banned “metabolic modulator”. Athletes are banned from using is during and between competitions.

The substance has been at the centre of several high-profile doping cases, with 23 Chinese swimmers having tested positive for TMZ in 2021, as well as Russian figure skater Kamila Valieva during the Beijing Winter Olympics.

Swiatek appealed the provisional suspension within 10 days of being told she had tested positive, exactly a month after the initial test in the build-up to the Cincinnati Open.

She missed the Korea Open, China Open and Wuhan Open during her provisional suspension, losing her world No 1 ranking in the process.

The ITIA also confirmed on Thursday that Swiatek will forfeit ranking points and prize money from the Cincinnati Open, although this will not affect her ranking.

Swiatek said: “This experience, the most difficult in my life so far, taught me a lot.

“The whole thing will definitely stay with me for the rest of my life, it took a lot of strength, returning to training after this situation nearly broke my heart.

“So there were many tears and lots of sleepless nights.”

A statement by the women’s professional tour (WTA) said: “The WTA fully supports Iga during this difficult time.

“Iga has consistently demonstrated a strong commitment to fair play and upholding the principles of clean sport, and this unfortunate incident highlights the challenges athletes face in navigating the use of medications and supplements.

“The WTA remains steadfast in our support for a clean sport and the rigorous processes that protect the integrity of competition.”

The ITIA also explained that the brevity of the ban related to the “incredibly low level of fault” on Swiatek’s part, who did almost everything possible to avoid an inadvertent positive test.

“She could perhaps have chosen to use a batch tested version of melatonin rather than the medication version from Poland. She could, in theory, have carried out her own batch testing,” said Karen Moorhouse, the ITIA chief executive.

“But in effect, that incredibly low level of fault is reflected in the penalty that she’s got, but it also reflects that strict liability responsibility of what you choose to take yourself.”