It was in 2018 that the IOC commissioned retesting of samples from the London Olympics six years earlier.
2727 samples were retested by the International Testing Agency (ITA), a process that has now resulted in a final report.
Over the years, individual names and sports have been published and several of the active ones were suspended several years before 2018. Now the ITA has made a total compilation of its results.
It is mainly about active people from Russia and Belarus and about the sports of weightlifting and athletics.
In total, 31 medals have been withdrawn: eight gold, 14 silver and nine bronze.
Most have been caught for anabolic steroids by long-acting metabolite (LTM) testing, something that could not be detected in 2012. A total of 73 doping violations were detected after testing methods were refined.
Russia is the worst offender, losing two golds, ten silvers and one bronze.
Kazakhstan loses four medals – all gold in weightlifting.