Chinese swimming star Ning Zetao (file photo)

BEIJING, June 27 (Xinhua) -- Chinese swimming star Ning Zetao will miss out on a chance to defend his world title at the upcoming world championships, after failing to meet the FINA Qualifying Time Standard A.

Ning, who came to stardom after winning men's 100 meter freestyle at the worlds back in 2015 in Kazan, clocked 49.67 seconds earlier this week in his 100m free heat in a trial for the Chinese National Games, in what was his first competitive race since last year's Olympic Games. But the 24-year-old then quit the final citing waist injury.

"Ning's result didn't beat the designated A cut time. He is not the top ranked swimmer among those who meet the B cut, so he is not eligible to compete at the world championships," said Zhao Jian, vice director of the Chinese Swimming Association.

The 2017 world championships are scheduled to take place in Budapest, Hungary from July 14 to 31.