Bao Chunlai, file photo. [Photo/Xinhua]

BEIJING, - Chinese left-hander Bao Chunlai, 28, announced his retirement from the international badminton ring, according to the Badminton World Federation (BWF) on Wednesday.

The world badminton governing body said on its official website that BWF had received his official retirement notice on September 20, 2011. "The lanky left-hander from China has announced his retirement from the international badminton scene at 28 years of age."

"Known for his graceful court coverage, Bao cited recurring knee injuries as the reason for his retirement."

Bao confirmed the retirement, telling that the injury had affected him for a long time, almost several years, and that he had no alternative but to make the decision.

The 28-year-old said that he submitted his retirement apply to Chinese team before last week' s China Badminton Masters and Chinese team had ratified his apply.

"I sent the retirement apply to BWF a few days ago, maybe they just received it, then they announced it on their website today," said Bao.

Bao suffered a downturn in recent years due to continual knee injury. He missed out on competing at the 2011 world championships in August, in which China made a clean-sweep of all five gold medals.

China head coach Li Yongbo said after the worlds that the Chinese line-up for the London Olympic Games will be from the shuttlers participated at the worlds, meaning Bao lost the chance to the London Olympic Games.

"I'm still training in the national team," said Bao, while his teammates were in Tokyo for the Japan Superseries.

Talking About whether he would represent his home town Hunan province to compete in the National Games in 2013, Bao said that depended on the negotiation with Hunan team.

Bao has been an especially valuable member of China's world champion Thomas Cup (men's international) teams of 2004, 2006 and 2008. He has medaled in three of the four world championships that he has played, earning a bronze in the 2003 and 2007 editions, and a silver in the 2006 Championships in Madrid

His performances in the Olympic Games have been somewhat disappointing. He was beaten in the round of 16 at the 2004 Athens Olympics and in the quarterfinals of the Beijing Olympics.