World Anti-Doping Agency (WADA) chief Craig Reedie has said new accusations of mass doping in athletics will "shake the foundation" of clean sport.
Reedie said at an International Olympic Committee (IOC) meeting here on Sunday that the numbers involved in new allegations had shocked him, reports news.com.au.
WADA said in a statement that it was "very alarmed" by the accusations broadcast by German television channel ARD and reported by Britain's Sunday Times.
Russian and Kenyan athletes featured strongly in the programme, aired just three weeks before the start of the World Championships in Beijing.
"WADA is very disturbed by these new allegations that have been raised by ARD which will, once again, shake the foundation of clean athletes worldwide," Reedie said.
Reedie said he would pass the allegations to an independent commission looking into separate allegations aired by ARD in December of widespread doping in Russian athletics.
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The new allegations said that leaked results from 12,000 blood tests on 5,000 competitors by the International Association of Athletics Federations (IAAF) showed the wide extent of cheating in the sport. The results come from an IAAF database leaked to the two media outlets.
Australian doping experts Michael Ashenden and Robin Parisotto concluded from the results that 800 athletes in disciplines from 800m to the marathon registered values considered suspicious or highly suspicious.
They also said the analysis of the blood levels of the medal-winners at world championships and Olympics between 2001 and 2012 indicated that a third of athletics medals were won by competitors who had given suspicious tests.