Two-time Grand Slam champion Simona Halep has questioned the “big difference” in how tennis doping cases are handled after world number two Iga Swiatek received a one-month ban.

The International Tennis Integrity Agency (ITIA) announced on Thursday that Swiatek had accepted a one-month suspension after testing positive for banned substance trimetazidine (TMZ).

Halep, who was out of action for more than 18 months following two separate anti-doping violations, has criticised the ITIA for having “completely different approaches”.

“I stand and ask myself, why is there such a big difference in treatment and judgment?” Halep posted on Instagram on Friday.

“I can’t find and I don’t think there can be a logical answer. It can only be bad will from ITIA, the organization that has done absolutely everything to destroy me despite the evidence.”

Halep was provisionally suspended in October 2022 after testing positive for banned substance roxadustat – an anti-anaemia drug which stimulates the production of red blood cells in the body.

The Romanian was later banned for four years – a period which was reduced to nine months in March after an appeal at the Court of Arbitration for Sport

Halep always maintained her innocence and argued she had taken a contaminated supplement.

“I lost two years of my career, I lost many nights when I couldn’t sleep, thoughts, anxiety, questions without answers,” the former world number one said.

“How is it possible that in identical cases happening around the same time, ITIA to have completely different approaches to my detriment?”

Swiatek tested positive for a heart medication, TMZ, in an out-of-competition sample in August 2024, when she was world number one.

The ITIA accepted the five-time major winner’s violation was caused by contamination of the regulated non-prescription medication melatonin, manufactured and sold in Poland, which Swiatek took for jet lag and sleep issues.

An ITIA spokesperson told BBC Sport there were “very important differences” between Halep’s case and Swiatek’s.

“No two cases are the same, they often involve different circumstances, and direct comparisons are not always helpful,” the ITIA said.

“The product contaminated in Ms Swiatek’s case was a regulated medication, not a supplement.”

Swiatek’s suspension comes after men’s world number one Jannik Sinner tested positive for clostebol in March.

Although the ITIA accepted there was “no fault or negligence” attached to the 23-year-old Italian, the World Anti-Doping Agency (Wada) has launched an appeal to Cas.

The ITIA said: “We deal with each case based on the facts and evidence, not a player’s name, ranking or nationality. When a prohibited substance is found in a player’s system, we investigate it thoroughly.

“We urge players to exercise extreme caution when taking supplements and we are always happy to answer any questions they have.”