South Korean swimming star Park Tae-hwan has been banned for 18 months by world swimming body FINA, after failing a drug test last year.

The ban was announced on Monday and will run until March 2, 2016. It rules Park out of this year’s world championships in Kazan, Russia, but allows him to compete at the Rio Olympics, reported Xinhua on Tuesday.

The 25-year-old swimmer tested positive for a banned anabolic steroid at an out-of-competition test before the Asian Games on September 3 last year.

FINA said Park’s results from September 3 onward will be annulled and prize money forfeited, which means he will have to return the three individual medals and three relay medals he won at 2014 Asian Games.

When the positive test was announced in January, Park’s representatives blamed it on an injection administered by a local hospital, which offered him free chiropractic and other treatments in July.

Park argued that he was given the injection without knowing what specific substances it contained, while the hospital said it did not know testosterone was a prohibited substance.

Park won the 400-metre freestyle at the 2008 Beijing Olympics. He also won silver in the 200-metre freestyle in Beijing and silvers in both events 400m and 200m at the 2012 London Games.