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.

ASADA has confirmed beyond doubt AOD9604 - a failed anti-obesity drug banned by WADA under its S0 category because it is not approved for human use - was used at the club. The report states players were largely unwitting victims of a high-risk and poorly governed program.

The ASADA investigation into Essendon is ongoing and the prospect of infraction notices for doping violations being issued to individual players or the wider team remains open.

However, any such decision would be weighed against evidence showing players acted in good faith and had been given poor advice and directions by Dank - who has refused to be interviewed by ASADA and others at the club.

The report will relieve Hird to the extent the evidence gathered portrays him as a person who never sought to break anti-doping rules or knowingly expose his players to harm. However, it is understood Hird is one of several officials identified as having failed to ensure proper practices were implemented and followed, exposing players to an unsafe workplace.

The circumstantial evidence about the use of thymosin beta 4 is further corroborated by an interview Dank gave to Fairfax Media in April in which he repeatedly talked about giving the drug to players.

Hours before publication of a story on April 12, Essendon told Fairfax Media it would dispute reports thymosin beta 4 was used because player consent forms only referred to ''thymosin'' and it was possible a version of the drug not banned by WADA had been used.

When contacted for further clarification by Fairfax Media prior to publication, Dank said he was mistaken in his original on-the-record interview and his references to thymosin beta 4 in fact related to a drug called Thymomodulin.

In his earlier on-the-record interview, Dank confirmed he used ''Thymosin BETA-4'' and did so because he said there was ''good data, very good data that supports Thymosin BETA-4 in the immune system''.

When questioned about ASADA's decision in April 2013 to publicly list ''Thymosin BETA-4'' as ''prohibited'', Dank responded: ''Well, that must have just only come in this year and I will get someone to speak to ASADA about that. That's just mind blowing.''

It is understood much of the testimony of Essendon's former high performance boss Dean Robinson has largely been corroborated by ASADA investigators, who interviewed several figures including Essendon coaching staff and external medical professionals who worked to varying degrees with Dank.

But the report reserves its most damning assessments for Dank, effectively accusing him of running a highly risky program that exposed players to possible doping violations or health risks.