Stephen Dank, the man at the centre of an investigation into the club's possible use of banned substances, has claimed the players were injected with nothing more than vitamins, and not given any illegal products, with or without their consent.

He said the program involved ''detailed discussion'' with coach James Hird and other members of the club's coaching and medical staff, and that everything the players were given was logged on the club's intranet site.

As he was speaking the parents of Essendon players were listening to the club's explanation. Parents were tight-lipped as they entered the administration department, with one mother, who wished to remain anonymous, saying she was ''hopeful'' of some answers.

Dank also claimed that after being interviewed by the Australian Crime Commission last September, before he was sacked by Essendon, he had satisfied investigators that he had not breached any rules.

''They were obviously quite happy with what I had discussed with them, and I figured that must have been consistent with whatever information they had. And they indicated to me they were happy with that information,'' said Dank.

''They said they didn't think I had done anything wrong.''

Dank, speaking on the ABC's 7.30, said he would often consult with Essendon players while a coach was present, and that they, club doctor Bruce Reid and suspended conditioning coach Dean Robinson were fully informed of the program.

He said some of the coaches - who are not bound by the World Anti-Doping Agency code - were taking supplements that would have been illegal for the players to take.

''Look, there were some differences in what we offered the coaches. Let's face it, the coaches themselves are not subjected to any WADA code. Off the top of my head three, four or five were taking vitamin supplements, protein supplements,'' he said.

''To be perfectly honest a couple of coaches were using supplements that were a little bit outside the WADA code but again, they were entitled to it and [there was] nothing illegal in those.''

Dank, whose work with rugby league club Manly has also been questioned, denied players were delivered intravenous peptides, and were in fact injected with vitamin B and D, both compliant with the code on performance-enhancing drugs.

He drew a clear line between his work with anti-ageing clinics and his work for Essendon, saying it was no different to a situation ''where a club doctor in his medical bag will carry certain things which will of course be prohibited in a sporting sense but they can use it in a therapeutic setting''.

Dank also said Essendon's players were fully informed throughout last season of the substances they were taking, and that the consent forms they signed reaffirmed their understanding of the program.

''Often at early times, particularly in the early stages, we'd get them to reaffirm what they were taking and what they were doing … there was a lot of discussion with the players on that,'' he said.

With BRENT DIAMOND