Many of the problems related to authorities not being able to locate particular athletes in the Olympic village to bring them in for out-of-competition testing. Of 5,380 doping tests planned to be carried out, only 4,882 were actually conducted. With Biological Passport blood tests, only 47 of 450 planned tests were carried out.
Sir Craig Reedie, WADA’s president, nonetheless insists that the Rio Olympics were “not tainted” despite the problems with drug testing.
Serious failings at Rio Olympics: here.
Reedie insists Games not tainted despite doping testing problems: here.