RIO DE JANEIRO — Fallout from the Russian doping scandal has provoked a public dispute among global sports officials, further fueling a controversy that has threatened to overshadow the start of the Rio Games this week.
On Sunday, the president of the International Olympic Committee, Thomas Bach, blamed the global antidoping watchdog for mishandling accusations that Russia had executed an elaborate cheating scheme dating back years. Mr. Bach said at a news conference here that the antidoping organization’s slow response had put sports officials in a bind so close to the Summer Olympics.