Former world number one Simona Halep has expressed dismay at the way Iga Świątek's doping case was handled compared to her own.

The International Tennis Integrity Agency (ITIA) announced this week Świątek tested positive for the prohibited substance trimetazidine, a heart medication known as TMZ, in an out-of-competition doping test in August.

The five-time major champion received a one-month suspension, with the ITIA accepting her explanation the positive result was unintentional and caused by the contamination of a non-prescription medication, melatonin.

Świątek claimed she was using the medication for issues with jet lag and sleeping.

Halep, who initially received a four-year ban for doping before launching a successful appeal, said Świątek's case was treated differently by tennis authorities.

"I sit and try to understand but it is really impossible for me to understand something like this," Halep posted on her Instagram account.

"I sit and wonder, 'Why such a big difference in treatment and judgement?'

"I can't find, and I don't think there can be, a logical answer.

"It can only be bad will on the part of ITIA, the organisation that did absolutely everything to destroy me despite the evidence."

Halep, who won the French Open in 2018 and Wimbledon in 2019, received a four-year suspension after testing positive for the banned drug roxadustat at the 2022 US Open.

Earlier this year, her suspension was reduced by the Court of Arbitration for Sport (CAS) to nine months after CAS accepted her explanation of a contaminated supplement.

"I have always believed in good, I have believed in the fairness of this sport, I have believed in kindness," Halep wrote on Instagram.

"The injustice that was done to me was painful, is painful and maybe will always be painful.

"How is it possible that in identical cases that happened at about the same time [of the season], ITIA has completely different approaches, to my detriment?"

Świątek's ban follows a similar case involving Jannik Sinner, the top-ranked men's player.

Sinner tested positive twice for an anabolic steroid in March but was not banned in an ITIA decision because the agency determined he was not to blame.

It led to claims by some observers of a two-tier system, with critics arguing it afforded Sinner protection because of his status as a leading player.

Earlier this month, ATP Tour chair Andrea Gaudenzi acknowledged there "could have been better communication" in explaining the rules involved in Sinner's doping case, but refuted allegations of double standards.

The decision to clear Sinner of wrongdoing, however, was appealed by the World Anti-Doping Agency (WADA) in September.

WADA is seeking a ban of one to two years and the Switzerland-based CAS is expected to make a final ruling on the case in 2025.

AP