SHANGHAI • Chinese swim star Ning Zetao will not defend his 100m freestyle world title next month after failing to qualify for the Budapest showpiece.

The fresh-faced Ning, a fan favourite in China after winning the world championship crown in 2015, clocked 49.67sec this week in his 100m free heat in a trial for the Chinese National Games.

The 24-year-old - hugely popular in China for his good looks as well as his success in the pool - then quit the final, citing a waist injury.

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

Ning was making his first competitive appearance since last year's Olympics, where he managed a 12th-place finish in the men's 100m freestyle and 30th-place in the 50m freestyle.

In February, he was reportedly kicked out of China's national swimming squad for violating several team rules, including signing sponsorship contracts without the team's consent.

It was not the first time he had made negative headlines. He served a one-year suspension after testing positive for the prohibited substance clenbuterol in 2011.

But he rose to the stardom when he became the first Asian to win the 100m free world title.

AGENCE FRANCE-PRESSE, XINHUA