23 athletes from London 2012 positive in doping retests
The results involved athletes from six different national teams four years ago.
BERLIN - Twenty-three athletes from five sports tested positive for banned drugs in re-checks of 265 samples from the 2012 London Olympics, the International Olympic Committee said on Friday.
The results, part of the IOC's re-testing of samples from past Games to keep cheats from competing at the Rio de Janeiro Olympics in August, involved athletes from six different national teams four years ago.
The IOC, which stores samples for a decade in order to re-test using newer methods or to look for new drugs, will not name the athletes or the sports until the second sample or B tests has been analysed. That process can take several weeks.
Last week the organisation found 31 athletes from six sports who could be banned from Rio for failing doping tests when 454 samples were re-examined from the 2008 Beijing Olympics.
The IOC, which said one more sample from Beijing had shown "abnormal parameters" and would also be followed up on, added that the re-testing programme was still in progress and could deliver more positive checks in the coming weeks.
"These re-analyses show, once again, our determination in the fight against doping," IOC President Thomas Bach said. "We want to keep the dopers away from the Olympic Games in Rio de Janeiro.
"I have already appointed a disciplinary commission which has the full power to take all the decisions on behalf of the IOC."
The targeted re-testing focused mainly on athletes who could potentially compete in Rio and the IOC said anyone found doping would be banned from those Games.
While the re-testing is yielding results, it also raises speculation about the extent of doping at the Games some two months before the Olympics.
Doping scandals have plagued the build-up to the world's biggest multi-sports event with Russia under investigation following a report by the World Anti-Doping Agency (WADA) suggesting systematic doping in that country.
Kenya, famed for its distance runners, is also racing against the clock to amend its anti-doping laws in order for WADA to rule the African nation as compliant again.
In a further blow to its credibility, Russia has confirmed 14 of the positive Beijing Games rechecks concerned their athletes, some of whom are medallists.
Russian track and field athletes are currently suspended pending an investigation into the scandal which could leave the nation without a full team at the Games starting on 5 August.
The IAAF, the world governing body of athletics, will decide on 17 June whether Moscow has done enough to clean up its act in order to be readmitted to competition.
Russia has pledged to ban all athletes with a doping past from its Olympic squad but calls for a blanket ban of the entire team have grown louder with every twist of the scandal.