Essendon witness calls charges political

A key witness in the doping case against Essendon Football Club claims the timing of his drug charges is politically motivated and says he has a strong defence.

Shane Charter, 46, questioned the timing of his trafficking and possessing steroids charges, which came just weeks after doping allegations were made against 34 past and present Essendon players.

"I feel it's somewhat ironic that I'm the one under investigation here today and there's possibly political overtones as to the timing of this arrest given the investigation into my activities was over a year old," he said outside the Melbourne Magistrates Court.

The former bodybuilder was due to appear in the court on Monday but his mention hearing was administratively adjourned until December.

Charter is a key witness in the Australian Sports Anti-Doping Authority's case against the 34 past and present Essendon players alleged to have taken the banned substance Thymosin beta 4.

He has been charged with one count each of trafficking and possessing steroids and multiple counts of possessing a schedule four poison.

"I'm here today to answer charges relating to medically prescribed growth hormone and anabolic steroid," Charter said.

"My doctor provided due diligence and followed correct protocol in legally writing scripts that for some reason the police deem not legal.

"Essendon Football Club had a chief medical officer who was bypassed, marginalised and even ignored to the detriment of the club."

ASADA issued show cause notices to the past and present Essendon players last month after the club lost its Federal Court challenge to have the joint ASADA-AFL investigation deemed illegal.

Essendon coach James Hird is appealing that decision.

Charter will now face a mention hearing on December 3.