China's top sport officials are confident the 2010 Guangzhou Asian Games will be "clean", despite a series of drug offenses involving some of the nation's top athletes this year.

In May, Chinese judoka Tong Wen, the champion in the women's over 78kg class at the Beijing Olympics, was suspended for two years for a positive test for clenbuterol.

Then, Li Fuyu, the nation's most prominent professional road cyclist and a Radioshack teammate of US legend Lance Armstrong, was confirmed as having failed a test for the same substance in August

Following that, former badminton women's single world No 1, Zhou Mi of Hong Kong, who used to play for the Chinese mainland, tested positive ahead of this month's badminton World Championships and received a two-year ban.

Last month, a German table tennis player also tested positive for clenbuterol, leading to a temporary ban. He blamed it on food he ate in Suzhou, Jiangsu province, while he took part in the China Open. However, Gong Jiming, vice head of the Suzhou municipal sports bureau, refuted the German's claim.

"All the cases indicate our anti-doping efforts have room to be improved, but we are confident we can eliminate drug scandals in the future," said Jiang Zhixue, chief of the science and education department of the State General Administration of Sports (SGAS), during an anti-doping summit at Beijing Sport University on Wednesday.

With only 43 days left before the Asiad gets under way on Nov 12 in Guangzhou, SGAS has vowed to implement the "toughest tests in history" to ensure a clean games.

"We will organize the strictest drug tests ever for the upcoming Guangzhou Asian Games to show the world we have not relaxed our alertness since the Beijing Olympics," said Duan Shijie, an SGAS deputy minister.

The forum was also attended by Arne Ljungqvist, the vice-president of the World Anti-Doping Agency. He launched his newly published memoirs: Anti-doping Defender, and said he appreciated China's anti-doping efforts over the past 20 years - especially at the Beijing Olympics.