The International Olympic Committee (IOC) says it has found 45 more cases of doping -- including many medalists -- from the 2008 Beijing and 2012 London Summer Olympics.
The IOC said in a statement on July 22 that a second wave of retests had discovered 30 positive cases from Beijing and 15 from London.
The IOC said the second wave focused mainly on medalists from those two Olympics, as 23 of the 45 new doping cases were from athletes who had won gold, silver, or bronze medals at the games.
The new cases mean that 98 Olympians have now failed a reanalysis of their stored samples from the previous two Summer Olympics.
"The new reanalysis once again shows the commitment of the IOC in the fight against doping," IOC President Thomas Bach said in a statement.
The IOC said 1,243 samples have been retested thus far using "the very latest scientific analysis methods."
The IOC is expected to announce a decision in the coming days on whether to ban Russia's entire Olympic team after reports of a state-sponsored and widespread program of doping by Russians.
The nationalities of the athletes who failed the most recent doping tests were not made available.