The IOC said the 23 positive re-tests were on athletes from six countries competing in five sports. This comes a week after it announced that 31 new cases had been found in the Beijing Olympics.
A statement issued by the International Olympic Committee (IOC) on Friday said that the positive results had come from re-tests, which were carried out on 265 selected doping samples based on intelligence-gathering that began in August of last year.
The IOC said all athletes found to have doped would be banned from competing at the summer Olympic Games in Rio de Janeiro in August.
"These reanalyses show, once again, our determination in the fight against doping. We want to keep the dopers away from the Olympic Games in Rio de Janeiro," IOC President Thomas Bach said.
"I have already appointed a disciplinary commission which has the full power to take all the decisions on behalf of the IOC."
Last week the IOC announced that 31 athletes from six sports could be banned from the Rio de Janeiro Games in August after failing doping tests when 454 samples were re-examined from the 2008 Beijing Olympics.
The IOC stores samples taken from athletes for a period of 10 years in order to allow for re-testing with newer methods or to look for new drugs. It has said that it will not identify the athletes or their sports until the 'b' tests on the samples have been completed - a process that can take several weeks.
pfd/kms (Reuters, dpa, AFP)