Liu Yang, the Chinese Olympic swimmer who won gold in the men's 100m butterfly at the Beijing Olympics, has undergone surgery to repair a torn ligament in his right knee.

The injury is believed to be a result of a fall during training on the day he was scheduled to compete in the 2014 World Championships in Barcelona.

Liu, 28, had been injured in an accident while practicing with the national team last year and had previously undergone surgery for a similar issue in 2013. He said that the latest surgery would allow him to return to competition as soon as possible.

Despite the setback, Liu remains optimistic about his chances of returning to the Olympics in Rio de Janeiro next year. "I am very confident that I can recover quickly," he told reporters after the news broke. "I will definitely go back to training and prepare myself well for the upcoming competitions."