The International Olympic Committee (IOC) will retest frozen samples from previous Games after an improved testing method led to hundreds of positive cases that went undetected, according to a German television channel.
China has planned to investigate an allegation that "99 percent of illegal substances" come from it but remains doubtful of the World Anti-Doping Agency`s statistics.
The World Anti-Doping Agency (WADA) has said it has had no approach from disgraced cyclist Lance Armstrong to indicate he is ready to admit using performance-enhancing drugs.
The World Anti-Doping Agency said new research findings expected this spring could suggest as many as 1 in 10 athletes who compete internationally may be doping.
BOA has refused to give into mounting pressure and lift its ban, raising the prospect of a legal battle with WADA and the International Olympic Committee (IOC).
Underworld controls a large proportion of world sport, WADA director general David Howman said.
Day in Pics: 25th October
Showbiz World - October 25, 2014
'Happy New Year' star cast perform in Washington