Essondon Coach James Hird under pressure as claims he took banned substances.

James Hird yesterday. Photo: Jason South

The South Yarra doctor who authorised blood tests for Essendon players at the request of sports scientist Stephen Dank has said it was "really weird" that he was used rather than club doctor Bruce Reid.

Amid other revelations in the growing scandal, Fairfax Media can reveal that:

■ Numerous text messages between coach James Hird and Mr Dank show the coach was told specific details about the supplement program, including the use of intravenous administration.

■ Australian Sports Anti-Doping Authority investigators are trying to build a doping case against Essendon over its use of anti-obesity drug AOD9604 and have sought information about a corporate presentation given last year by the drug's maker to Hird and club chairman David Evans.

The suspected freezing out of Dr Reid from the Bombers' supplement program is a key part of the serious internal governance failings at the club that contributed to players being exposed to potential health and doping risks.

It is understood that Dr Reid, who has been at the club for many years and is close to many of its senior officials, has been interviewed at length by ASADA investigators about his concerns over the supplement program, in which players were injected with or otherwise administered a range of unusual supplements.

Another club doctor, Brendan De Morton, has also been interviewed by ASADA.

Dr Reid has provided ASADA with copious notes of practices that worried him and warnings he gave. He said he voiced misgivings to several administrators at the club and key football department personnel.

He also reported that he wrote to the board with his concerns, although it is uncertain whether the Essendon directors were ever made aware of that letter.

South Yarra doctor Robin Willcourt has told Fairfax Media that it was unusual he was called on as an external doctor by Mr Dank. Dr Willcourt has said he signed off on forms for the players to get blood tests at the request of Mr Dank, who asked for his informal advice on improving player health.

An anti-ageing and sports nutrition doctor who is a former medical director at Adelaide's Queen Elizabeth Hospital pregnancy centre, Dr Willcourt said:"I agree that looking at it now, it is really weird that they didn't get the club doctor to sign off on the requests. But at the time, I didn't think much about it. The whole issue of doping was the farthest thing from my mind."

He never treated or met any players, never signed off on any prescriptions and did not order or administer any supplements to players.

He said that, at the request of Mr Dank, he "informally reviewed" player blood test results compiled by a pathologist.

"I looked at the blood-work of about 20 players and gave my comments, like, 'This guy needs his growth hormone up or his testosterone up.'" The pair had also discussed what supplements could achieve the desired results.

The revelations come after AFL chief Andrew Demetriou and David Evans said action would be taken against any Essendon club official found to have acted improperly in exposing players to potentially risky supplement practices.

They were responding to reports on Thursday in Fairfax Media about Hird's strong backing and encouragement of Mr Dank's supplement program, as well as claims from the sports scientist that Hird was also injected with supplements, including one banned for use in players by doping authorities.

The reports also revealed that Hird was told by Mr Dank specific details about what players were being given, the fact they were being injected with supplements and the desire to give more supplements to older or injured players.

Fairfax also reported what the Essendon players had been given, including a peptide extracted from pig's brain, the first milk from a mother cow, and anti-obesity drug AOD9604, which Mr Dank said he used to help injured players.

Mr Dank has denied his work led to the breaching of any doping laws or exposed any player to harm.

ASADA continues to investigate Essendon's use of AOD9604, having been given interim advice from the World Anti-Doping Agency that it was banned at the time of use under a catch-all rule that prohibits supplements not approved for therapeutic use.

Among the information sought by ASADA is a corporate presentation given last year by the drug's maker, Calzada, to Hird and Evans, who owns a broking firm. It is understood Evans attended the briefing, which detailed the potential of AOD and Calzada's other products, at the request of Hird after the coach spoke to Mr Dank.

No investment was made in Calzada as a result of the briefing and the same presentation was given to other broking firms.

ASADA is aware of legal advice that raises concerns about the prospects of any AOD9604 action succeeding and may yet abandon its probe into the use of the drug.