has learned the fate of her doping case moments after winning her fourth-round match at the Australian Open.

The International Tennis Integrity Agency previously ruled that the world No. 2 bore "no significant fault or negligence" after testing positive for the banned substance trimetazidine in August.

She successfully proved that the positive test was the result of contamination via melatonin medication

The World Anti-Doping Agency still had the power to appeal the outcome but the body has now confirmed that it will not be appealing.

In a statement released on Monday WADA confirmed its decision not to lodge an appeal to the Court of Arbitration for Sport and confirmed that, following a review, Swiatek's explanation for contamination was "plausible".

"WADA has conducted a full review of the case file related to the ITIA decision, which it received on 29 November. WADA's scientific experts have confirmed that the specific contaminated melatonin scenario, as presented by the athlete and accepted by the ITIA, is plausible and that there would be no scientific grounds to challenge it at CAS," the statement read.

"Further, WADA sought advice from external legal counsel, who considered that the athlete's contamination explanation was well evidenced, that the ITIA decision was compliant with the World Anti-Doping Code, and that there was no reasonable basis to appeal it to the CAS."

Swiatek tested positive in an out-of-competition sample in August last year. She was then notified of the positive test and handed a provisional suspension on September 12.

The five-time Grand Slam champion ended up missing three tournaments during the Asian swing as a result. On September 22, she lodged an appeal and notified an independent tribunal that she had found the source of contamination.

Her provisional suspension was lifted on October 4 and she was allowed to continue playing. If a player successfully appeals their provisional suspension, details of this ban and the anti-doping violation are not made public until the case has concluded.

The ITIA did not oppose this ban being lifted.

Following an investigation, the body accepted that the positive test was caused by contamination via "regulated non-prescription medication (melatonin), manufactured and sold in Poland that the player had been taking for jet lag and sleep issues".

The case resulted in a "no significant fault or negligence finding" and the ITIA offered Swiatek a one-month suspension as punishment, which she accepted on November 27.

The 22 days she served during the provisional suspension counted towards her final ban. She served eight more days and her ban was lifted on December 4.

WADA's announcement came moments after Swiatek stepped off the court at the Australian Open after beating lucky loser Eva Lys 6-0 6-1.

The world No. 2 is now through to the quarter-final to face eighth seed Emma Navarro. After learning that WADA would not be appealing, Swiatek said: "For sure I'm just satisfied that I can get a closure, kind of, and I can just move on and, like, finish this whole process, because, you know, I just want to play tennis and focus on the tournament. So, yeah, I'm just satisfied."