"It is increasingly clear that far more IAAF staff knew about the problems than has currently been acknowledged," said the report, written by former WADA head Dick Pound and presented at a news conference in Munich.
"It is not credible that elected officials were unaware of the situation affecting ... Athletics in Russia. If, therefore, the circle of knowledge was so extensive why was nothing done? Quite obviously there was no appetite on the part of the IAAF to challenge Russia."
The report laid considerable blame at the feet of the IAAF Council, the overseeing body that included the now president of the IAAF, Sebastian Coe.
Coe was in the audience as Pound presented his findings.
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The report said council members "could not have been unaware of the level of nepotism that operated within the IAAF," and also "could not have been unaware of the extent of doping."
The report found that former IAAF president Lamine Diack "was responsible for organizing and enabling the conspiracy and corruption" that took place at IAAF.
Pound's first report, issued in November, detailed a state-sponsored doping program in Russia involving corruption and cover-ups. That led the IAAF to suspend Russia's track and field federation, leaving its athletes in danger of missing this year's Olympics in Rio de Janeiro.