SINGAPORE (AFP) -- Singapore's first and only-ever Olympic champion Joseph Schooling will not be competing at the Asian Games in Hangzhou next month, the swimmer said on Saturday, Aug. 5.

Singapore's Joseph Schooling. (AFP)

"While I will not be participating, I wish the contingent the best at Asian Games and to do Singapore proud," the 28-year-old said in a statement.

"The status of my training and competition remains the same. More details of my future will be shared in due course."

Singapore Aquatics told The Straits Times newspaper that two swimmers had clocked faster times than Schooling during the qualification window for the games.

AFP has reached out to the association for comment.

Schooling had pulled out of the Southeast Asian Games held in May, saying he was "not at the level" to do his best.

The swimmer, who has been performing two years of mandatory military service, was mired in a drug controversy last year. He tested negative, but confessed to consuming cannabis overseas.

Singapore has some of the toughest drug laws in the world, and its citizens and permanent residents face up to 10 years in prison if found to have consumed illegal substances outside the city-state.

Schooling was given a warning and placed on a supervised urine test regime for six months.

He was also made no longer eligible for leave or disruption to train or compete during his military service.

Schooling caused a sensation at Rio 2016 when he beat Michael Phelps to win the 100m butterfly.

He failed to qualify for the same event at Tokyo 2020, however, and has dropped several hints that his career is coming to an end.

The 2022 Asian Games -- postponed by a year because of China's strict zero-Covid rules -- will be held in Hangzhou from September 23 to October 8.