In a lengthy statement on Instagram, Kyrgios said the last few years of injuries had taken “a huge toll on me, both mentally and physically”.
“My body hasn’t been able to do what my mind expects it to do,” he wrote.
“Coming to terms with being near the end of my career has been harder than I ever imagined.
“None of that excuses what I did.”
Kyrgios said he would be stepping away from social media and public life for the next 28 days to “focus on getting myself right”.
Cocaine is classified as a stimulant and substance of abuse on the World Anti-Doping Agency’s prohibited list.
Reduced sanctions apply for athletes who test positive for the substance out of competition.
However, Kyrgios’ sample was submitted during a tournament in which he played singles, ultimately losing in the first round to Adam Walton.
“I’m sorry to my fans, my family, my sponsors and everyone close to me,” Kyrgios added.
“Above all, I’m sorry to the kids who follow me. I know the example this sets and I’m deeply disappointed in myself.”
Kyrgios has long been a controversial figure in tennis.
His behaviour on court has been widely criticised and he has been given numerous large fines for smashing racquets, making audible obscenities and arguing with the umpire.
In 2023, he admitted assaulting an ex-girlfriend two years earlier. He avoided a criminal conviction.
He was criticised further for making a series of comments which have been considered misogynistic.
In 2024 he shared a post from controversial influencer Andrew Tate. He later said he had gone “to all lengths” to distance himself from the self-proclaimed misogynist.
Kyrgios was also critical of the handling of two high-profile anti-doping cases involving top players Jannik Sinner and Iga Swiatek, calling them “disgusting” for tennis.
Kyrgios has won seven ATP Tour singles titles and reached the Wimbledon final in 2022, losing in four sets to Novak Djokovic.
He and compatriot Thanasi Kokkinakis won the Australian Open men’s doubles title together in 2022.
Kyrgios has also spoken about his struggles with mental health, saying he “genuinely contemplated” suicide and spent time in a psychiatric hospital in London after losing at Wimbledon in 2019.
