BEIJING (Reuters) - China will investigate claims that virtually all the raw materials used to produce illegal performance-enhancing drugs come from the country, even if they have serious reservations about their accuracy, state media said on Tuesday.

World Anti-Doping Agency (WADA) director general David Howman told Reuters in an interview last week that "ninety-nine percent" of the materials used by criminal gangs around the world to make the drugs were emanating from China.

David Howman, President of the World Anti-Doping Agency (WADA) attends a news conference during the European Commission Sport Forum in Budapest February 22, 2011. REUTERS/Laszlo Balogh

"We are shocked at Mr. Howman's comment," Jiang Zhixue, the head of anti-doping at China's sports ministry, told the official Xinhua news agency.

"We are wondering where this 99 percent came from and what is his evidence. We have asked for a more detailed explanation from WADA."

Jiang said the probe would require coordination from various ministries as had happened in a crackdown on the manufacture and sale of banned performance-enhancing substances in the run-up to the 2008 Beijing Olympics.

China's record on doping at elite levels of sport improved markedly after Beijing won the right to hold the 2008 Games, a far cry from the 1990s when the country's rise to sporting superpower was accompanied by regular scandals.

(Reporting by Nick Mulvenney in Sydney, editing by Patrick Johnston)

• Please wait.

• Sarawakian Daniel makes a winning return from injury
• ‘Comeback king’ Timothy lands his second title
• Pistorius rules out track return this year - report
• Seven more Al Zarooni horses test positive
• Lowe reunited with Hamilton at Mercedes
• F1 tyre changes to be less dramatic than feared
• Golf: Johnson triumphs by one stroke at Mobile Bay LPGA
• Results worldwide
• Bradley clings to lead in Texas with surging Korean one stroke adrift
• Classy Williams sweeps Azarenka aside in final