Corruption was "embedded" in the world athletics body IAAF and its leaders had to be aware of doping scandals in Russia and other countries, the World Anti-Doping Agency (WADA) has said in the second part of its report into doping and corruption in athletics.
Lamine Diack, the former president of the International Association of Athletics Federations (IAAF), was responsible for organising and enabling the conspiracy and corruption that took place in athletics' governing body, according to WADA's report.
Mr Diack, who was replaced by Sebastian Coe as president last August, is under investigation by French police for corruption and was heavily criticised in WADA's first report.
The report prepared by former WADA president Richard Pound said Mr Diack "sanctioned and appeared to have had personal knowledge of the fraud and the extortion of athletes carried out by the actions of the illegitimate governance structure he put in place".
It said the IAAF's governance process was inadequate to prevent corruption, and the checks and balances of good governance were missing.
"The corruption was embedded in the organisation," the report said.
"The IAAF Council could not have been unaware of the extent of doping in athletics and the non-enforcement of applicable anti-doping rules."
Current IAAF president Sebastian Coe was a vice-president during the corruption years involving Mr Diack.
The report stated that it was "increasingly clear" that far more IAAF staff knew about the problems than has so far been acknowledged.
"The IAAF was insufficiently firm in dealing with a number of countries including Russia" in the enforcement of doping tests and rules, the report said.
It said it was "completely improper governance" to allow supervision of suspected Russian doping cases to be separately managed by the IAAF President's personal legal counsel.
The former head of the Russian Athletics Federation, Valentin Balakhnichev, said the WADA report contained no evidence of corruption during his tenure.
Mr Balakhnichev said there was no point in waiting for a fair decision from WADA and IAAF, R-Sport news agency reported.
Athletics has already been tossed into turmoil by the first WADA report and French authorities placing former IAAF president Lamine Diack under formal investigation on suspicion of corruption and money laundering.
Diack's son Papa and two Russian officials last week were banned from the sport for life by an IAAF ethics board for covering up an elite Russian athlete's positive dope test and blackmailing her over it.
French prosecutors are investigating Diack, his son, as well as the former head of anti-doping Gabriel Dolle and Diack's lawyer on suspicion of corruption and will also give an update on their investigation on Thursday following the WADA commission news conference.
Accusations of systematic, state-sponsored doping and related corruption in Russia were detailed in an initial report by the WADA commission, leading to the IAAF banning the Russian athletics federation from the sport.
Chairman of the independent commission Dick Pound has said Coe and fellow IAAF vice president Sergey Bubka could have done more to push for reforms at the federation.
"They had an opportunity a long time ago to address issues of governance," Pound said in an interview with Britain's The Times newspaper.