WADA-banned substances AOD9604 and thymosin beta 4 were given to some Essendon players under the direction of sports scientist Stephen Dank, according to circumstantial evidence detailed in the confidential ASADA report into the club's 2012 supplements program.

Multiple sources aware of the contents of the report told Fairfax Media it detailed the strong faith Essendon coaching and management staff, including James Hird, placed in Dank and his assurance the program complied with the rules - a claim he maintains.

ASADA has also found Essendon staff failed to implement basic governance, management and medical practices to ensure players were not exposed to health and doping risks, and said the club failed to follow its own protocols around the review and use of drugs suggested by Dank.

Basic records about what drugs were given to specific players were not kept. This failure has made it more difficult for anti-doping investigators to build a prima facie case that could enable infraction notices to be issued to individuals.

A source who has read the ASADA report, said the circumstantial evidence was very strong that thymosin beta 4 - a drug deemed by the World Anti-Doping Agency to be performance enhancing - was given to several players at the club. Eleven players have told ASADA they were given what they were told was thymosin, although they could not say what sort of thymosin it was.