GWANGJU – Shayna Jack, who withdrew from the Australia team ahead of the world swimming championships, said she had tested positive for a banned substance on Saturday.
"It is with great sadness and heartache that I had to leave due to allegations of having a prohibited substance in my system," the 20-year-old freestyle swimmer wrote on Instagram.
"I did NOT take this substance knowingly. Swimming has been my passion since I was 10 years old and I would never intentionally take a banned substance that would disrespect my sport and jeopardise my career.
"Now there is an ongoing investigation and my team and I are doing everything we can to find out when and how this substance has come into contact with my body," added Jack.
Team mate Cate Campbell said she had been in the dark about the positive test but added that Jack's absence from the worlds was proof of Australia's anti-doping commitment.